bugfix for #51. ManagebusManagementThread now never accesses or changes the JAVAFX view-backing ObservableList but using a concurrenthasmap which drives the Tableview backing list with snapshots

src/main/java/kst4contest/controller/ChatController.java

@@ -24,6 +24,7 @@ import kst4contest.logic.PriorityCalculator;
 import kst4contest.model.*;
 import kst4contest.test.MockKstServer;
 import kst4contest.utils.PlayAudioUtils;
+import kst4contest.locatorUtils.Location;
 import kst4contest.view.Kst4ContestApplication;
 
 import java.io.*;
@@ -34,6 +35,7 @@ import java.util.function.Predicate;
 
 
 
+
 /**
  * 
  * Central Chat kst4contest.controller. Instantiate only one time per category of kst Chat.
@@ -318,10 +320,8 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 
 		EnumSet<Band> offered = EnumSet.noneOf(Band.class);
 
-		synchronized (getLst_chatMemberList()) {
+		for (ChatMember cm : findActiveChatMembersByRawCall(callRaw)) {
-			for (ChatMember cm : getLst_chatMemberList()) {
 			if (cm == null || cm.getCallSignRaw() == null) continue;
-				if (!normalizeCallRaw(cm.getCallSignRaw()).equals(callRaw)) continue;
 
 			Map<Band, ChatMember.ActiveFrequencyInfo> map = cm.getKnownActiveBands();
 			if (map == null || map.isEmpty()) continue;
@@ -340,11 +340,9 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 							+ " freq=" + e.getValue().frequency
 							+ " ageMs=" + age);
 				}
+			}
+		}
 
-
-				}
-			}
-		}
 		return offered;
 	}
 
@@ -356,10 +354,8 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 
 		EnumSet<Band> worked = EnumSet.noneOf(Band.class);
 
-		synchronized (getLst_chatMemberList()) {
+		for (ChatMember cm : findActiveChatMembersByRawCall(callRaw)) {
-			for (ChatMember cm : getLst_chatMemberList()) {
 			if (cm == null || cm.getCallSignRaw() == null) continue;
-				if (!normalizeCallRaw(cm.getCallSignRaw()).equals(callRaw)) continue;
 
 			if (cm.isWorked144())  worked.add(Band.B_144);
 			if (cm.isWorked432())  worked.add(Band.B_432);
@@ -368,9 +364,9 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 			if (cm.isWorked3400()) worked.add(Band.B_3400);
 			if (cm.isWorked5600()) worked.add(Band.B_5760);
 			if (cm.isWorked10G())  worked.add(Band.B_10G);
-				if (cm.isWorked24G())  worked.add(Band.B_24G); // optional, only if your Band enum supports it
+			if (cm.isWorked24G())  worked.add(Band.B_24G);
-			}
 		}
+
 		return worked;
 	}
 
@@ -645,7 +641,8 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 
 //            rotatorClient.
 
-			this.lst_chatMemberList.clear();;
+//			this.lst_chatMemberList.clear();;
+			this.clearActiveChatMembers();
 			this.lst_clusterMemberList.clear();
 
 			this.setDisconnected(true);
@@ -713,7 +710,7 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 			}
 		} else if (action.equals(ApplicationConstants.DISCSTRING_DISCONNECTONLY)){
 
-			this.lst_chatMemberList.clear();;
+			this.clearActiveChatMembers();
 			this.lst_clusterMemberList.clear();
 
 
@@ -959,16 +956,9 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 		if (targetCallsignRaw == null || targetCallsignRaw.isBlank()) {
 			return null;
 		}
-		String normalizedTargetCall = normalizeCallRaw(targetCallsignRaw);
+
-		synchronized (getLst_chatMemberList()) {
+		List<ChatMember> matchingMembers = findActiveChatMembersByRawCall(targetCallsignRaw);
-			for (ChatMember member : getLst_chatMemberList()) {
+		return matchingMembers.isEmpty() ? null : matchingMembers.get(0);
-				if (member == null || member.getCallSignRaw() == null) continue;
-				if (normalizeCallRaw(member.getCallSignRaw()).equals(normalizedTargetCall)) {
-					return member;
-				}
-			}
-		}
-		return null;
 	}
 
 	private String resolveSkedTargetLocator(String targetCallsignRaw) {
@@ -976,22 +966,43 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 			return null;
 		}
 
-		String normalizedTargetCall = normalizeCallRaw(targetCallsignRaw);
+		for (ChatMember member : findActiveChatMembersByRawCall(targetCallsignRaw)) {
-		synchronized (getLst_chatMemberList()) {
-			for (ChatMember member : getLst_chatMemberList()) {
-				if (member == null || member.getCallSignRaw() == null) continue;
-				if (!normalizeCallRaw(member.getCallSignRaw()).equals(normalizedTargetCall)) continue;
-
 			String locator = member.getQra();
 			if (locator != null && !locator.isBlank()) {
 				return locator.trim().toUpperCase(Locale.ROOT);
 			}
 		}
-		}
 
 		return null;
 	}
 
+//	private ChatMember resolveSkedTargetMember(String targetCallsignRaw) {
+//		if (targetCallsignRaw == null || targetCallsignRaw.isBlank()) {
+//			return null;
+//		}
+//
+//		List<ChatMember> matchingMembers = findActiveChatMembersByRawCall(targetCallsignRaw);
+//		return matchingMembers.isEmpty() ? null : matchingMembers.get(0);
+//
+//	}
+//
+//	private String resolveSkedTargetLocator(String targetCallsignRaw) {
+//		if (targetCallsignRaw == null || targetCallsignRaw.isBlank()) {
+//			return null;
+//		}
+//
+//		String normalizedTargetCall = normalizeCallRaw(targetCallsignRaw);
+//
+//		for (ChatMember member : findActiveChatMembersByRawCall(targetCallsignRaw)) {
+//			String locator = member.getQra();
+//			if (locator != null && !locator.isBlank()) {
+//				return locator.trim().toUpperCase(Locale.ROOT);
+//			}
+//		}
+//
+//		return null;
+//	}
+
 	public StationMetricsService getStationMetricsService() {
 		return stationMetricsService;
 	}
@@ -1014,10 +1025,14 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 		return new HashMap<>(lastInboundCategoryByCallSignRaw);
 	}
 
+//	public List<ChatMember> snapshotChatMembers() {
+//		synchronized (getLst_chatMemberList()) {
+//			return new ArrayList<>(getLst_chatMemberList());
+//		}
+//	}
+
 	public List<ChatMember> snapshotChatMembers() {
-		synchronized (getLst_chatMemberList()) {
+		return new ArrayList<>(activeChatMembersByCallAndCategory.values());
-			return new ArrayList<>(getLst_chatMemberList());
-		}
 	}
 
 	public List<ContestSked> snapshotActiveSkeds() {
@@ -1126,13 +1141,27 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 	private ObservableList<ChatMember> chatMemberList = FXCollections.observableArrayList(); // List of active stations
 
 
-	private ObservableList<ChatMember> lst_chatMemberList = FXCollections.synchronizedObservableList(chatMemberList); // List
 																														// of active stn in chat
 	private FilteredList<ChatMember> lst_chatMemberListFiltered = new FilteredList<ChatMember>(chatMemberList);
 	private SortedList<ChatMember> lst_chatMemberSortedFilteredList = new SortedList<ChatMember>(lst_chatMemberListFiltered);
+
+	private ObservableList<ChatMember> lst_chatMemberList = FXCollections.synchronizedObservableList(chatMemberList); // List
 	private ObservableList<Predicate<ChatMember>> lst_chatMemberListFilterPredicates = FXCollections.observableArrayList();
 	private ObservableList<ClusterMessage> lst_clusterMemberList = FXCollections.observableArrayList();
 
+	/*
+	 * Thread-safe active-member model.
+	 *
+	 * MessageBusManagementThread must not use the JavaFX TableView backing list as
+	 * its primary data model. Otherwise every add/remove fires FilteredList,
+	 * SortedList and TableView selection listeners on the MessageBus thread and JavaFX
+	 * can throw "Not on FX application thread" or internal listener NPEs.
+	 *
+	 * This map is the worker-thread safe source of truth. The ObservableList below
+	 * remains a UI mirror and is mutated only on the JavaFX application thread.
+	 */
+	private final java.util.concurrent.ConcurrentMap<String, ChatMember> activeChatMembersByCallAndCategory =
+			new java.util.concurrent.ConcurrentHashMap<>();
 
 	/*
 	 * Message table update buffers.
@@ -1161,6 +1190,239 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 	// ******************************************************************************************************************************************
 
 
+	/**
+	 * Executes UI-bound work on the JavaFX application thread.
+	 *
+	 * Worker threads may call this safely. If the caller is already on the FX
+	 * thread, the action is executed immediately to preserve ordering.
+	 */
+	private void runOnFxThread(Runnable action) {
+		if (action == null) {
+			return;
+		}
+
+		if (Platform.isFxApplicationThread()) {
+			action.run();
+		} else {
+			Platform.runLater(action);
+		}
+	}
+
+	/**
+	 * Builds the active-member key. The raw/base callsign alone is not enough
+	 * because the same station can be logged into multiple ON4KST categories at
+	 * the same time. Therefore the category number is part of the key.
+	 */
+	private String buildActiveChatMemberKey(String callSign, ChatCategory category) {
+		String normalizedCallsign = ChatMember.normalizeCallSignToBaseCallSign(callSign);
+		if (normalizedCallsign == null || normalizedCallsign.isBlank()) {
+			return null;
+		}
+
+		int categoryNumber = category == null ? -1 : category.getCategoryNumber();
+		return normalizedCallsign.trim().toUpperCase(Locale.ROOT) + "|" + categoryNumber;
+	}
+
+	private String buildActiveChatMemberKey(ChatMember member) {
+		if (member == null) {
+			return null;
+		}
+
+		String callSign = member.getCallSignRaw() != null ? member.getCallSignRaw() : member.getCallSign();
+		return buildActiveChatMemberKey(callSign, member.getChatCategory());
+	}
+
+	/**
+	 * Adds or replaces an active chat member in the worker-thread model and mirrors
+	 * that change to the JavaFX list. This is the only supported path for ON4KST
+	 * user-enter events.
+	 */
+	public void addOrUpdateActiveChatMember(ChatMember member) {
+		String key = buildActiveChatMemberKey(member);
+		if (key == null) {
+			return;
+		}
+
+		activeChatMembersByCallAndCategory.put(key, member);
+
+		runOnFxThread(() -> {
+			int existingIndex = findChatMemberIndexInUiListByKey(key);
+			if (existingIndex >= 0) {
+				lst_chatMemberList.set(existingIndex, member);
+			} else {
+				lst_chatMemberList.add(member);
+			}
+		});
+	}
+
+	/**
+	 * Removes an active chat member from the worker-thread model and from the UI
+	 * mirror. Removal from the ObservableList is always performed on the FX thread
+	 * because the list is bound to FilteredList/SortedList/TableView.
+	 */
+	public boolean removeActiveChatMember(ChatMember member) {
+		String key = buildActiveChatMemberKey(member);
+		if (key == null) {
+			return false;
+		}
+
+		ChatMember removedMember = activeChatMembersByCallAndCategory.remove(key);
+		runOnFxThread(() -> lst_chatMemberList.removeIf(currentMember -> key.equals(buildActiveChatMemberKey(currentMember))));
+		return removedMember != null;
+	}
+
+	/**
+	 * Clears the active-member model and the JavaFX UI mirror. Use this instead of
+	 * getLst_chatMemberList().clear() from timers or worker threads.
+	 */
+	public void clearActiveChatMembers() {
+		activeChatMembersByCallAndCategory.clear();
+		runOnFxThread(() -> lst_chatMemberList.clear());
+	}
+
+	/**
+	 * Resolves a member from the thread-safe active model. This avoids reading the
+	 * TableView backing list from MessageBusManagementThread.
+	 */
+	public ChatMember findActiveChatMember(ChatMember lookForThis) {
+		String key = buildActiveChatMemberKey(lookForThis);
+		return key == null ? null : activeChatMembersByCallAndCategory.get(key);
+	}
+
+	public ChatMember findActiveChatMember(String callSign, ChatCategory category) {
+		String key = buildActiveChatMemberKey(callSign, category);
+		return key == null ? null : activeChatMembersByCallAndCategory.get(key);
+	}
+
+	public int getActiveChatMemberCount() {
+		return activeChatMembersByCallAndCategory.size();
+	}
+
+	/**
+	 * Returns all active category variants of a callsign. This is used when a QRG or
+	 * band hint should be propagated from one category instance to the same station
+	 * in another category.
+	 */
+	public List<ChatMember> findActiveChatMembersByRawCall(String callSignRaw) {
+		String normalizedCallsign = ChatMember.normalizeCallSignToBaseCallSign(callSignRaw);
+		if (normalizedCallsign == null || normalizedCallsign.isBlank()) {
+			return Collections.emptyList();
+		}
+
+		String normalizedKeyPart = normalizedCallsign.trim().toUpperCase(Locale.ROOT);
+		List<ChatMember> matchingMembers = new ArrayList<>();
+
+		for (ChatMember member : activeChatMembersByCallAndCategory.values()) {
+			if (member == null) {
+				continue;
+			}
+
+			String memberCall = member.getCallSignRaw() != null ? member.getCallSignRaw() : member.getCallSign();
+			String normalizedMemberCall = ChatMember.normalizeCallSignToBaseCallSign(memberCall);
+			if (normalizedMemberCall != null && normalizedMemberCall.equalsIgnoreCase(normalizedKeyPart)) {
+				matchingMembers.add(member);
+			}
+		}
+
+		return matchingMembers;
+	}
+
+	/**
+	 * Updates locator and derived direction values in the active model. The UI list
+	 * contains the same member object, but the user-list refresh is still triggered
+	 * on the JavaFX thread so TableView/map derived displays can repaint safely.
+	 */
+	public boolean updateActiveChatMemberLocator(ChatMember lookupMember, String newLocator) {
+		ChatMember activeMember = findActiveChatMember(lookupMember);
+		if (activeMember == null) {
+			return false;
+		}
+
+		activeMember.setQra(newLocator);
+		activeMember.setQrb(new Location().getDistanceKmByTwoLocatorStrings(chatPreferences.getStn_loginLocatorMainCat(), newLocator));
+		activeMember.setQTFdirection(new Location(chatPreferences.getStn_loginLocatorMainCat()).getBearing(new Location(newLocator)));
+		fireUserListUpdate("Locator changed");
+		return true;
+	}
+
+	public boolean updateActiveChatMemberState(ChatMember lookupMember, int newState) {
+		ChatMember activeMember = findActiveChatMember(lookupMember);
+		if (activeMember == null) {
+			return false;
+		}
+
+		activeMember.setState(newState);
+		fireUserListUpdate("User state changed");
+		return true;
+	}
+
+	/**
+	 * Applies a UM3-style user-info update to an already known member. If ON4KST
+	 * sends the update before the matching enter message, the member is added so
+	 * later CH messages can resolve sender/receiver immediately.
+	 */
+	public void updateOrAddActiveChatMemberInfo(ChatMember updatedMember) {
+		String key = buildActiveChatMemberKey(updatedMember);
+		if (key == null) {
+			return;
+		}
+
+		ChatMember activeMember = activeChatMembersByCallAndCategory.get(key);
+		if (activeMember == null) {
+			addOrUpdateActiveChatMember(updatedMember);
+			return;
+		}
+
+		activeMember.setName(updatedMember.getName());
+		activeMember.setQra(updatedMember.getQra());
+		activeMember.setState(updatedMember.getState());
+		activeMember.setLastActivity(updatedMember.getLastActivity());
+		activeMember.setActivityTimeLastInEpoch(updatedMember.getActivityTimeLastInEpoch());
+		activeMember.setQrb(updatedMember.getQrb());
+		activeMember.setQTFdirection(updatedMember.getQTFdirection());
+		fireUserListUpdate("User info updated");
+	}
+
+	/**
+	 * Stores a newly detected QRG/band on all active category variants of a station.
+	 * The old StringProperty is still set for compatibility with existing TableView
+	 * columns and DXCluster code.
+	 */
+	public void applyDetectedFrequencyToActiveMembers(ChatMember sender, Band detectedBand, double detectedFrequencyMhz) {
+		if (sender == null || detectedBand == null || detectedFrequencyMhz <= 0) {
+			return;
+		}
+
+		String displayFrequency = String.valueOf(detectedFrequencyMhz);
+		String rawCall = sender.getCallSignRaw() != null ? sender.getCallSignRaw() : sender.getCallSign();
+
+		for (ChatMember member : findActiveChatMembersByRawCall(rawCall)) {
+			if (member == null) {
+				continue;
+			}
+			member.addKnownFrequency(detectedBand, detectedFrequencyMhz);
+			member.setFrequency(new SimpleStringProperty(displayFrequency));
+		}
+
+		// Also cover dummy senders that are not in the active model, e.g. [n/a] senders.
+		sender.addKnownFrequency(detectedBand, detectedFrequencyMhz);
+		sender.setFrequency(new SimpleStringProperty(displayFrequency));
+		fireUserListUpdate("Frequency detected");
+	}
+
+	private int findChatMemberIndexInUiListByKey(String key) {
+		if (key == null) {
+			return -1;
+		}
+
+		for (int i = 0; i < lst_chatMemberList.size(); i++) {
+			if (key.equals(buildActiveChatMemberKey(lst_chatMemberList.get(i)))) {
+				return i;
+			}
+		}
+		return -1;
+	}
+
 
 
 
@@ -2011,7 +2273,7 @@ public class ChatController implements ThreadStatusCallback, PstRotatorEventList
 							socket.close();
 							
 							chatController.setConnectedAndLoggedIn(false);
-							chatController.getLst_chatMemberList().clear();
+							chatController.clearActiveChatMembers();
 
 							System.out.println("[Chatcontroller, Warning: ] Socket closed or disconnected");
 						

src/main/java/kst4contest/controller/MessageBusManagementThread.java

@@ -324,31 +324,12 @@ public class MessageBusManagementThread extends Thread {
 			// --- STEP 3: Process Result ---
 			if (finalDetectedBand != null && finalDetectedFrequency > 0) {
 
-				// 1. Store in the new Map (for future context/history)
+				/*
-
+				 * Store the detected QRG in the thread-safe active-member model.
-				sender.addKnownFrequency(finalDetectedBand, finalDetectedFrequency);
+				 * The UI table is only a JavaFX mirror, so the MessageBus must not scan
-				// No automatic full terrain analysis here.
+				 * or mutate getLst_chatMemberList() here.
-				// The frequency is stored for later map/manual reachability requests.
+				 */
-
+				client.applyDetectedFrequencyToActiveMembers(sender, finalDetectedBand, finalDetectedFrequency);
-				//propagate known frequency to all instances of the same callsign (callRaw may exist multiple times)
-				try {
-					ArrayList<Integer> sameCallIdx = client.checkListForChatMemberIndexesByCallSign(sender);
-					for (int idx : sameCallIdx) {
-						ChatMember cm = client.getLst_chatMemberList().get(idx);
-						if (cm != null && cm != sender) {
-							cm.addKnownFrequency(finalDetectedBand, finalDetectedFrequency);
-							// No automatic full terrain analysis here.
-							// Avoids exhausting the online terrain API when many stations mention QRGs.
-						}
-					}
-				} catch (Exception e) {
-					System.out.println("[SmartParser, warning]: failed to propagate known frequency across duplicates: " + e.getMessage());
-				}
-
-
-				// 2. Set the old String-Property for GUI compatibility
-				// We assume standard display format (MHz)
-				sender.setFrequency(new javafx.beans.property.SimpleStringProperty(String.valueOf(finalDetectedFrequency)));
 
 				System.out.println("[SmartParser] Detected for " + sender.getCallSign() + ": " +
 						finalDetectedFrequency + " MHz (" + finalDetectedBand + ") " +
@@ -491,6 +472,92 @@ public class MessageBusManagementThread extends Thread {
 		return -1; // if it´s not found, the method will always end here and return -1
 	}
 
+	/**
+	 * Creates a minimal receiver object for ON4KST broadcast messages.
+	 * Keeping this as an object, not null, protects all downstream chat filters
+	 * and debug logging from null receiver paths.
+	 */
+	private ChatMember createAllReceiver() {
+		ChatMember dummy = new ChatMember();
+		dummy.setCallSign("ALL");
+		dummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
+		return dummy;
+	}
+
+	/**
+	 * Resolves a message sender from the thread-safe active-member model. If a
+	 * CH/CR message arrives before the matching user-enter message, a marked
+	 * fallback sender is used. The returned sender is never null.
+	 */
+	private ChatMember resolveInboundSender(String senderCallSign, ChatCategory category, ChatMessage message) {
+		ChatMember lookup = new ChatMember();
+		lookup.setCallSign(senderCallSign);
+		lookup.setChatCategory(category);
+
+		ChatMember senderObj = this.client.findActiveChatMember(lookup);
+		if (senderObj != null) {
+			senderObj.setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
+
+			// Remember the last active category so later outgoing replies can be routed correctly.
+			this.client.rememberLastInboundCategory(senderObj.getCallSignRaw(), senderObj.getChatCategory());
+
+			// Metrics influence priority scoring; process them after message text is known.
+			this.client.getStationMetricsService().onInboundMessage(
+					senderObj.getCallSignRaw(),
+					System.currentTimeMillis(),
+					message == null ? null : message.getMessageText(),
+					this.client.getChatPreferences(),
+					this.client.getChatPreferences().getStn_loginCallSign()
+			);
+
+			this.client.getScoreService().requestRecompute("rx-chat-message");
+			return senderObj;
+		}
+
+		ChatMember fallbackSender = new ChatMember();
+		String myCall = this.client.getChatPreferences().getStn_loginCallSign();
+		if (senderCallSign != null && senderCallSign.equalsIgnoreCase(myCall)) {
+			fallbackSender.setCallSign(myCall);
+		} else {
+			fallbackSender.setCallSign("[n/a]" + senderCallSign);
+		}
+		fallbackSender.setChatCategory(category);
+		fallbackSender.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
+		return fallbackSender;
+	}
+
+	/**
+	 * Resolves a message receiver from the active-member model. Unknown receivers
+	 * are represented as explicit fallback objects instead of null. This keeps PM
+	 * echo display and historic messages stable even if the target station already
+	 * left the chat.
+	 */
+	private ChatMember resolveInboundReceiver(String receiverCallSign, ChatCategory category) {
+		if (receiverCallSign == null || receiverCallSign.equals("0")) {
+			return createAllReceiver();
+		}
+
+		ChatMember lookup = new ChatMember();
+		lookup.setCallSign(receiverCallSign);
+		lookup.setChatCategory(category);
+
+		ChatMember receiverObj = this.client.findActiveChatMember(lookup);
+		if (receiverObj != null) {
+			return receiverObj;
+		}
+
+		ChatMember fallbackReceiver = new ChatMember();
+		String myCall = this.client.getChatPreferences().getStn_loginCallSign();
+		if (receiverCallSign.equalsIgnoreCase(myCall)) {
+			fallbackReceiver.setCallSign(myCall);
+		} else {
+			fallbackReceiver.setCallSign(receiverCallSign + "(left)");
+		}
+		fallbackReceiver.setChatCategory(category);
+		fallbackReceiver.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
+		return fallbackReceiver;
+	}
+
 	/**
 	 * Processes received messages via port 23001 (improved telnet Interface)
 	 *
@@ -590,7 +657,7 @@ public class MessageBusManagementThread extends Thread {
 
 
 				if (!client.getChatPreferences().getStn_loginCallSign().equals(newMember.getCallSign())) {
-					this.client.getLst_chatMemberList().add(newMember); //the own call will not be in the list
+					this.client.addOrUpdateActiveChatMember(newMember); // the own call will not be in the list
 //					this.client.getReachabilityService().ensureAutoTropoMarginCalculated(newMember);
 					// Reachability is calculated on demand only: map click, selected station, or manual request.
 				}
@@ -637,7 +704,7 @@ public class MessageBusManagementThread extends Thread {
 
 						newMember = this.client.getDbHandler().fetchChatMemberWkdDataForOnlyOneCallsignFromDB(newMember);
 
-					this.client.getLst_chatMemberList().add(newMember);
+						this.client.addOrUpdateActiveChatMember(newMember);
 //					this.client.getReachabilityService().ensureAutoTropoMarginCalculated(newMember);
 
 						this.client.getDbHandler().storeChatMember(newMember);
@@ -665,17 +732,11 @@ public class MessageBusManagementThread extends Thread {
 						newMember.setCallSign(splittedMessageLine[2]);
 
 						System.out.println("[MSGBUSMGT, Info:] User left Chat and will be removed from list ["
-						+ this.client.getLst_chatMemberList().size() + "] :" + newMember.getCallSign());
+								+ this.client.getActiveChatMemberCount() + "] :" + newMember.getCallSign());
-				try {
-					this.client.getLst_chatMemberList().remove(
-							checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), newMember));
 
-					//since 1.26 new method design to detect chatcategory, too!
+						if (!this.client.removeActiveChatMember(newMember)) {
-
+							System.out.println("[MSGBUSMGT, Info:] User sent left chat but was not active: "
-				} catch (Exception e) {
+									+ newMember.getCallSign() + " / " + newMember.getChatCategory());
-					System.out.println("[MSGBUSMGT, EXC!, Error:] User sent left chat but had not been there ... ["
-							+ this.client.getLst_chatMemberList().size() + "] :" + newMember.getCallSign() + "\n"
-							+ e.getStackTrace());
 						}
 
 					} else
@@ -695,9 +756,12 @@ public class MessageBusManagementThread extends Thread {
 
 							chategoryForMessageAndMessageSender = newMessageArrived.getChatCategory();
 							newMessageArrived.setMessageGeneratedTime(splittedMessageLine[2]);
+							newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
+							newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 							if (splittedMessageLine[3].equals("SERVER")) {
 								ChatMember dummy = new ChatMember();
+								dummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
 								dummy.setCallSign("SERVER");
 								dummy.setName("Sysop");
 								newMessageArrived.setSender(dummy);
@@ -707,77 +771,16 @@ public class MessageBusManagementThread extends Thread {
 
 							} else {
 
-					ChatMember sender = new ChatMember();
+								newMessageArrived.setSender(resolveInboundSender(
-					sender.setCallSign(splittedMessageLine[3]);
+										splittedMessageLine[3],
-					sender.setChatCategory(chategoryForMessageAndMessageSender);
+										chategoryForMessageAndMessageSender,
-
+										newMessageArrived));
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), sender);
-
-
-					if (index != -1) {
-						//user not found in the chatmember list
-						try {
-//							newMessageArrived.setSender(this.client.getLst_chatMemberList().get(index)); // set sender to member of
-//							this.client.getLst_chatMemberList().get(index).setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							ChatMember senderObj = this.client.getLst_chatMemberList().get(index);
-							newMessageArrived.setSender(senderObj);
-							senderObj.setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							// Remember last inbound category per callsignRaw (required for correct send-routing later)
-							this.client.rememberLastInboundCategory(senderObj.getCallSignRaw(), senderObj.getChatCategory());
-
-							// Metrics for scoring: momentum, response-time, no-reply, positive signals
-							this.client.getStationMetricsService().onInboundMessage(
-									senderObj.getCallSignRaw(),
-									System.currentTimeMillis(),
-									newMessageArrived.getMessageText(),
-									this.client.getChatPreferences(),
-									this.client.getChatPreferences().getStn_loginCallSign()
-							);
-
-							// Activity/category changes influence priority => request recompute
-							this.client.getScoreService().requestRecompute("rx-chat-message");
-
-						} catch (Exception exc) {
-							ChatMember aSenderDummy = new ChatMember();
-							aSenderDummy.setCallSign(splittedMessageLine[3] + "[n/a]");
-							aSenderDummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
-							newMessageArrived.setSender(aSenderDummy);
-							System.out.println("MsgBusmgtT: Catched Error! " + exc.getMessage() + " // " + splittedMessageLine[3] + " is not in the list! Faking sender!");
-							exc.printStackTrace();
-						}
-																								// b4 init list
-					} else {
-						//user not found in chatmember list, mark it, sender can not be set
-						if (!sender.getCallSign().equals(this.client.getChatPreferences().getStn_loginCallSign().toUpperCase())) {
-							sender.setCallSign("[n/a]" + sender.getCallSign());
-							// if someone sent a message without being in the userlist (cause
-							// on4kst missed implementing....), callsign will be marked
-						} else {
-							//that means, message was by own station, broadcasted to all other
-							ChatMember dummy = new ChatMember();
-							dummy.setCallSign("ALL");
-							newMessageArrived.setReceiver(dummy);
-
-							AirPlaneReflectionInfo preventNullpointerExc = new AirPlaneReflectionInfo();
-							preventNullpointerExc.setAirPlanesReachableCntr(0);
-							sender.setAirPlaneReflectInfo(preventNullpointerExc);
-							newMessageArrived.setSender(sender); //my own call is the sender
-						}
 							}
 
-//					newMessageArrived.setSender(this.client.getChatMemberTable().get(splittedMessageLine[3]));
-				}
-
-				newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
-				newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 							if (splittedMessageLine[7].equals("0")) {
-					// message is not directed to anyone, move it to the cq messages!
+								// message is not directed to anyone, move it to the cq messages.
-					ChatMember dummy = new ChatMember();
+								newMessageArrived.setReceiver(createAllReceiver());
-					dummy.setCallSign("ALL");
-					newMessageArrived.setReceiver(dummy);
 
 								this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
 
@@ -786,36 +789,9 @@ public class MessageBusManagementThread extends Thread {
 							} else {
 								//message is directed to another chatmember, process as such!
 
-					ChatMember receiver = new ChatMember();
+								newMessageArrived.setReceiver(resolveInboundReceiver(
-
+										splittedMessageLine[7],
-					receiver.setChatCategory(chategoryForMessageAndMessageSender); //got out of message itself
+										chategoryForMessageAndMessageSender));
-
-					receiver.setCallSign(splittedMessageLine[7]);
-
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), receiver);
-
-					if (index != -1) {
-						newMessageArrived.setReceiver(this.client.getLst_chatMemberList().get(index));// -1: Member left Chat
-																								// before...
-					} else { //found in active member list
-
-
-						if (receiver.getCallSign().equals(client.getChatPreferences().getStn_loginCallSign())) {
-							/**
-							 * If mycallsign sent a message to the server, server will publish that message and
-							 * send it to all chatmember including me.
-							 * As mycall is not in the userlist,  the message would not been displayed if I handle
-							 * it in the next case (marking left user, just for information). But I want an echo.
-							 */
-
-							receiver.setCallSign(client.getChatPreferences().getStn_loginCallSign());
-							newMessageArrived.setReceiver(receiver);
-						} else {
-							//this are user which left chat but had been adressed by this message
-							receiver.setCallSign(receiver.getCallSign() + "(left)");
-							newMessageArrived.setReceiver(receiver);
-						}
-					}
 
 //					System.out.println("message directed to: " + newMessageArrived.getReceiver().getCallSign() + ". EQ?: " + this.client.getownChatMemberObject().getCallSign() + " sent by: " + newMessageArrived.getSender().getCallSign().toUpperCase() + " -> EQ?: "+ this.client.getChatPreferences().getLoginCallSign().toUpperCase());
 
@@ -979,7 +955,21 @@ public class MessageBusManagementThread extends Thread {
 										// the "to me message list" with modified messagetext, added rxers callsign
 
 									} else {
-							//message sent to other user
+										/*
+										 * Message sent from one other station to another other station.
+										 *
+										 * The old code reached this point only with members from the visible user list.
+										 * With explicit fallback sender/receiver objects, this path may also see
+										 * stations that already left the chat or arrived before their user-list entry.
+										 * In that case locators may be missing, so angle/range analysis and DX spotting
+										 * must be skipped while the chat message itself is still published.
+										 */
+										boolean senderHasLocator = newMessageArrived.getSender().getQra() != null
+												&& !newMessageArrived.getSender().getQra().isBlank();
+										boolean receiverHasLocator = newMessageArrived.getReceiver().getQra() != null
+												&& !newMessageArrived.getReceiver().getQra().isBlank();
+
+										if (senderHasLocator && receiverHasLocator) {
 											if (DirectionUtils.isInAngleAndRange(client.getChatPreferences().getStn_loginLocatorMainCat(),
 													newMessageArrived.getSender().getQra(),
 													newMessageArrived.getReceiver().getQra(),
@@ -998,7 +988,7 @@ public class MessageBusManagementThread extends Thread {
 												if (client.getChatPreferences().isNotify_dxClusterServerEnabled()) {
 													try {
 														if (newMessageArrived.getSender().getFrequency() != null) {
-                                            //TODO: testing for next version 3.33: addinitional information will be displayed in cluster if there is such an information
+															//TODO: testing for next version 3.33: additional information will be displayed in cluster if there is such information
 															ChatMember onlyForSpottingObject = new ChatMember();
 															onlyForSpottingObject.setCallSign(newMessageArrived.getSender().getCallSign());
 															onlyForSpottingObject.setFrequency(newMessageArrived.getSender().getFrequency());
@@ -1014,11 +1004,10 @@ public class MessageBusManagementThread extends Thread {
 																			newMessageArrived.getSender().getAirPlaneReflectInfo().getRisingAirplanes().get(1).getPotential() + "%");
 																}
 															} else {
-
 																onlyForSpottingObject.setQra(newMessageArrived.getSender().getQra());
 															}
 
-											this.client.getDxClusterServer().broadcastSingleDXClusterEntryToLoggers(onlyForSpottingObject); //tells the DXCluster server to send a DXC message for this member to the logbook software
+															this.client.getDxClusterServer().broadcastSingleDXClusterEntryToLoggers(onlyForSpottingObject);
 														}
 													} catch (Exception exception) {
 														System.out.println("[MSGBUSMGT, ERROR:] DXCluster messageserver error while processing spot for 0: " + newMessageArrived.getSender().getCallSign() + " // " + exception.getMessage());
@@ -1036,14 +1025,21 @@ public class MessageBusManagementThread extends Thread {
 														" ; sender bearing to me: " + new Location(newMessageArrived.getSender().getQra()).getBearing(new Location(client.getChatPreferences().getStn_loginLocatorMainCat())));
 												newMessageArrived.getSender().setInAngleAndRange(false);
 											}
+										} else {
+											newMessageArrived.getSender().setInAngleAndRange(false);
+											System.out.println("[MSGBUSMGT, Info:] Skipping angle/range analysis for message with missing locator: "
+													+ newMessageArrived.getSender().getCallSign() + " -> "
+													+ newMessageArrived.getReceiver().getCallSign());
+										}
 
 //							this.client.getLst_globalChatMessageList().add(0, newMessageArrived);
 										this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
 //						System.out.println("MSGBS bgfx: tx call = " + newMessageArrived.getSender().getCallSign() + " / rx call = " + newMessageArrived.getReceiver().getCallSign());
 									}
 								} catch (NullPointerException referenceDeletedByUserLeftChatDuringMessageprocessing) {
-						System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: " + referenceDeletedByUserLeftChatDuringMessageprocessing.getStackTrace());
+									System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: "
-//						referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
+											+ referenceDeletedByUserLeftChatDuringMessageprocessing.getMessage());
+									referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
 								}
 
 								// sdtout to me message-List
@@ -1062,7 +1058,8 @@ public class MessageBusManagementThread extends Thread {
 										+ " " + newMessageArrived.getSender().getCallSign() + ", " + newMessageArrived.getMessageSenderName() + " -> "
 										+ newMessageArrived.getReceiver().getCallSign() + ": " + newMessageArrived.getMessageText());
 							} catch (Exception exceptionOccured) {
-					System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage() + "\n" + exceptionOccured.getStackTrace());
+								System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage());
+								exceptionOccured.printStackTrace();
 							}
 
 							// --- Band/QRG recognition (fills ChatMember.knownActiveBands) ---
@@ -1085,24 +1082,21 @@ public class MessageBusManagementThread extends Thread {
 								temp4.setQra(splittedMessageLine[3]);
 								temp4.setLastActivity(new Utils4KST().time_generateActualTimeInDateFormat());
 
-				int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), temp4);
+								ChatMember foundThisInChatMemberList = this.client.findActiveChatMember(temp4);
-
+								if (foundThisInChatMemberList == null && this.client.getChatCategorySecondChat() != null) {
-				if (index != -1) {
+									/*
+									 * LOC messages do not carry the category. The old implementation checked
+									 * only the main category. Try the second active category as a fallback so
+									 * dual-channel operation can still update locator changes.
+									 */
+									temp4.setChatCategory(this.client.getChatCategorySecondChat());
+									foundThisInChatMemberList = this.client.findActiveChatMember(temp4);
+								}
 
+								if (foundThisInChatMemberList != null) {
 									System.out.println("[MSGBUSMGT:] Locator Change of [" + (splittedMessageLine[2] + "], old was: "
-							+ this.client.getLst_chatMemberList().get(index).getQra() + " new is: "
+											+ foundThisInChatMemberList.getQra() + " new is: " + splittedMessageLine[3]));
-							+ splittedMessageLine[3]));
+									this.client.updateActiveChatMemberLocator(temp4, splittedMessageLine[3]);
-
-					ChatMember foundThisInChatMemberList = this.client.getLst_chatMemberList().get(index); //make less list accesses
-
-//					this.client.getLst_chatMemberList().get(index).setQra(splittedMessageLine[3]);
-//					this.client.getLst_chatMemberList().get(index).setQrb(new Location().getDistanceKmByTwoLocatorStrings(client.getChatPreferences().getLoginLocator(), splittedMessageLine[3]));
-//					this.client.getLst_chatMemberList().get(index).setQTFdirection(new Location(client.getChatPreferences().getLoginLocator()).getBearing(new Location(splittedMessageLine[3])));
-
-					foundThisInChatMemberList.setQra(splittedMessageLine[3]);
-					foundThisInChatMemberList.setQrb(new Location().getDistanceKmByTwoLocatorStrings(client.getChatPreferences().getStn_loginLocatorMainCat(), splittedMessageLine[3]));
-					foundThisInChatMemberList.setQTFdirection(new Location(client.getChatPreferences().getStn_loginLocatorMainCat()).getBearing(new Location(splittedMessageLine[3])));
-
 								} else {
 									System.out.println("[MSGBUSMGT:] ERROR! Locator Change of ["
 											+ (splittedMessageLine[2] + "] is not possible, user is not in the Table!"));
@@ -1232,11 +1226,9 @@ public class MessageBusManagementThread extends Thread {
 
 												stateChangeMember.setChatCategory(util_getChatCategoryByCategoryNrString(splittedMessageLine[1]));
 
-				int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(),
+												if (!this.client.updateActiveChatMemberState(stateChangeMember, stateChangeMember.getState())) {
-						stateChangeMember);
+													System.out.println("[MSGBUSMGT, Info:] State change for inactive user: "
-
+															+ stateChangeMember.getCallSign() + " / " + stateChangeMember.getChatCategory());
-				if (index != -1 && index != 0) {
-					this.client.getLst_chatMemberList().get(index).setState(stateChangeMember.getState());
 												}
 
 //				this.client.getChatMemberTable().get(stateChangeMember.getCallSign())
@@ -1266,14 +1258,9 @@ public class MessageBusManagementThread extends Thread {
 
 //					System.out.println("[MSGBUSMGT:] DXCluster Message detected ");
 
-				int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(),
+													// -1 could be the case if mycall is processed; own call is not displayed in the active-member list.
-						stateChangeMember);
+													if (!client.getChatPreferences().getStn_loginCallSign().equalsIgnoreCase(stateChangeMember.getCallSign())) {
-
+														this.client.updateOrAddActiveChatMemberInfo(stateChangeMember);
-				//-1 could be the case if mycall is processed
-				if (index != -1) {
-					this.client.getLst_chatMemberList().get(index).setName(stateChangeMember.getName());
-					this.client.getLst_chatMemberList().get(index).setQra(stateChangeMember.getQra());
-					this.client.getLst_chatMemberList().get(index).setState(stateChangeMember.getState());
 													}
 
 												} else
@@ -1297,6 +1284,8 @@ public class MessageBusManagementThread extends Thread {
 
 														chategoryForMessageAndMessageSender = newMessageArrived.getChatCategory();
 														newMessageArrived.setMessageGeneratedTime(splittedMessageLine[2]);
+														newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
+														newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 														if (splittedMessageLine[3].equals("SERVER")) {
 															ChatMember dummy = new ChatMember();
@@ -1309,76 +1298,16 @@ public class MessageBusManagementThread extends Thread {
 
 														} else {
 
-					ChatMember sender = new ChatMember();
+															newMessageArrived.setSender(resolveInboundSender(
-					sender.setCallSign(splittedMessageLine[3]);
+																	splittedMessageLine[3],
-					sender.setChatCategory(chategoryForMessageAndMessageSender);
+																	chategoryForMessageAndMessageSender,
-
+																	newMessageArrived));
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), sender);
-
-					if (index != -1) {
-						//user not found in the chatmember list
-						try {
-//							newMessageArrived.setSender(this.client.getLst_chatMemberList().get(index)); // set sender to member of
-//							this.client.getLst_chatMemberList().get(index).setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							ChatMember senderObj = this.client.getLst_chatMemberList().get(index);
-							newMessageArrived.setSender(senderObj);
-							senderObj.setActivityTimeLastInEpoch(new Utils4KST().time_generateCurrentEpochTime());
-
-							// Remember last inbound category per callsignRaw (required for correct send-routing later)
-							this.client.rememberLastInboundCategory(senderObj.getCallSignRaw(), senderObj.getChatCategory());
-
-							// Metrics for scoring: momentum, response-time, no-reply, positive signals
-							this.client.getStationMetricsService().onInboundMessage(
-									senderObj.getCallSignRaw(),
-									System.currentTimeMillis(),
-									newMessageArrived.getMessageText(),
-									this.client.getChatPreferences(),
-									this.client.getChatPreferences().getStn_loginCallSign()
-							);
-
-							// Activity/category changes influence priority => request recompute
-							this.client.getScoreService().requestRecompute("rx-chat-message");
-
-						} catch (Exception exc) {
-							ChatMember aSenderDummy = new ChatMember();
-							aSenderDummy.setCallSign(splittedMessageLine[3] + "[n/a]");
-							aSenderDummy.setAirPlaneReflectInfo(new AirPlaneReflectionInfo());
-							newMessageArrived.setSender(aSenderDummy);
-							System.out.println("MsgBusmgtT: Catched Error! " + exc.getMessage() + " // " + splittedMessageLine[3] + " is not in the list! Faking sender!");
-							exc.printStackTrace();
-						}
-						// b4 init list
-					} else {
-						//user not found in chatmember list, mark it, sender can not be set
-						if (!sender.getCallSign().equals(this.client.getChatPreferences().getStn_loginCallSign().toUpperCase())) {
-							sender.setCallSign("[n/a]" + sender.getCallSign());
-							// if someone sent a message without being in the userlist (cause
-							// on4kst missed implementing....), callsign will be marked
-						} else {
-							//that means, message was by own station, broadcasted to all other
-							ChatMember dummy = new ChatMember();
-							dummy.setCallSign("ALL");
-							newMessageArrived.setReceiver(dummy);
-
-							AirPlaneReflectionInfo preventNullpointerExc = new AirPlaneReflectionInfo();
-							preventNullpointerExc.setAirPlanesReachableCntr(0);
-							sender.setAirPlaneReflectInfo(preventNullpointerExc);
-							newMessageArrived.setSender(sender); //my own call is the sender
-						}
 														}
 
-//					newMessageArrived.setSender(this.client.getChatMemberTable().get(splittedMessageLine[3]));
-				}
-
-				newMessageArrived.setMessageSenderName(splittedMessageLine[4]);
-				newMessageArrived.setMessageText(splittedMessageLine[6]);
 
 														if (splittedMessageLine[7].equals("0")) {
-					// message is not directed to anyone, move it to the cq messages!
+															// message is not directed to anyone, move it to the cq messages.
-					ChatMember dummy = new ChatMember();
+															newMessageArrived.setReceiver(createAllReceiver());
-					dummy.setCallSign("ALL");
-					newMessageArrived.setReceiver(dummy);
 
 //					this.client.getLst_globalChatMessageList().add(0, newMessageArrived); // sdtout to all message-List
 															this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
@@ -1386,35 +1315,9 @@ public class MessageBusManagementThread extends Thread {
 														} else {
 															//message is directed to another chatmember, process as such!
 
-					ChatMember receiver = new ChatMember();
+															newMessageArrived.setReceiver(resolveInboundReceiver(
-
+																	splittedMessageLine[7],
-					receiver.setChatCategory(chategoryForMessageAndMessageSender); //got out of message itself
+																	chategoryForMessageAndMessageSender));
-
-					receiver.setCallSign(splittedMessageLine[7]);
-
-					int index = checkListForChatMemberIndexByCallSign(this.client.getLst_chatMemberList(), receiver);
-
-					if (index != -1) {
-						newMessageArrived.setReceiver(this.client.getLst_chatMemberList().get(index));// -1: Member left Chat
-						// before...
-					} else { //found in active member list
-
-						if (receiver.getCallSign().equals(client.getChatPreferences().getStn_loginCallSign())) {
-							/**
-							 * If mycallsign sent a message to the server, server will publish that message and
-							 * send it to all chatmember including me.
-							 * As mycall is not in the userlist,  the message would not been displayed if I handle
-							 * it in the next case (marking left user, just for information). But I want an echo.
-							 */
-
-							receiver.setCallSign(client.getChatPreferences().getStn_loginCallSign());
-							newMessageArrived.setReceiver(receiver);
-						} else {
-							//this are user which left chat but had been adressed by this message
-							receiver.setCallSign(receiver.getCallSign() + "(left)");
-							newMessageArrived.setReceiver(receiver);
-						}
-					}
 
 //					System.out.println("message directed to: " + newMessageArrived.getReceiver().getCallSign() + ". EQ?: " + this.client.getownChatMemberObject().getCallSign() + " sent by: " + newMessageArrived.getSender().getCallSign().toUpperCase() + " -> EQ?: "+ this.client.getChatPreferences().getLoginCallSign().toUpperCase());
 
@@ -1447,7 +1350,16 @@ public class MessageBusManagementThread extends Thread {
 
 																} else {
 																	//message sent to other user
-							if (DirectionUtils.isInAngleAndRange(client.getChatPreferences().getStn_loginLocatorMainCat(),
+																	// message sent from one other station to another other station
+																	boolean senderHasLocator = newMessageArrived.getSender().getQra() != null
+																			&& !newMessageArrived.getSender().getQra().isBlank();
+
+																	boolean receiverHasLocator = newMessageArrived.getReceiver().getQra() != null
+																			&& !newMessageArrived.getReceiver().getQra().isBlank();
+
+																	if (senderHasLocator && receiverHasLocator) {
+																		if (DirectionUtils.isInAngleAndRange(
+																				client.getChatPreferences().getStn_loginLocatorMainCat(),
 																				newMessageArrived.getSender().getQra(),
 																				newMessageArrived.getReceiver().getQra(),
 																				client.getChatPreferences().getStn_maxQRBDefault(),
@@ -1456,17 +1368,24 @@ public class MessageBusManagementThread extends Thread {
 																			newMessageArrived.getSender().setInAngleAndRange(true);
 
 																		} else {
-
+																			newMessageArrived.getSender().setInAngleAndRange(false);
+																		}
+																	} else {
+																		/*
+																		 * Historic fallback senders/receivers may not have locators.
+																		 * The message is still valid and should be displayed, but angle/range
+																		 * analysis cannot be calculated without both locators.
+																		 */
 																		newMessageArrived.getSender().setInAngleAndRange(false);
 																	}
 
-//							this.client.getLst_globalChatMessageList().add(0, newMessageArrived);
+																	this.client.publishChatMessage(newMessageArrived);
-							this.client.publishChatMessage(newMessageArrived); // sdtout to all message-List (new from v1.7)
 //						System.out.println("MSGBS bgfx: tx call = " + newMessageArrived.getSender().getCallSign() + " / rx call = " + newMessageArrived.getReceiver().getCallSign());
 																}
 															} catch (NullPointerException referenceDeletedByUserLeftChatDuringMessageprocessing) {
-						System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: " + referenceDeletedByUserLeftChatDuringMessageprocessing.getStackTrace());
+																System.out.println("MSGBS bgfx, <<<catched error>>>: referenced user left the chat during messageprocessing or message got before user entered chat message: "
-//						referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
+																		+ referenceDeletedByUserLeftChatDuringMessageprocessing.getMessage());
+																referenceDeletedByUserLeftChatDuringMessageprocessing.printStackTrace();
 															}
 
 															// sdtout to me message-List
@@ -1479,7 +1398,8 @@ public class MessageBusManagementThread extends Thread {
 																	+ " " + newMessageArrived.getSender().getCallSign() + ", " + newMessageArrived.getMessageSenderName() + " -> "
 																	+ newMessageArrived.getReceiver().getCallSign() + ": " + newMessageArrived.getMessageText());
 														} catch (Exception exceptionOccured) {
-					System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage() + "\n" + exceptionOccured.getStackTrace());
+															System.out.println("[MSGMgtBus: ERROR CHATCHED ON MAYBE NULL ISSUE]: " + exceptionOccured.getMessage());
+															exceptionOccured.printStackTrace();
 														}
 
 														// --- Band/QRG recognition (fills ChatMember.knownActiveBands) ---
@@ -1534,7 +1454,7 @@ public class MessageBusManagementThread extends Thread {
 
 
 																for (int i = 0; i < 10; i++) {
-					client.getLst_globalChatMessageList().add(pwErrorMsg);
+																	client.publishChatMessage(pwErrorMsg);
 //					client.getLst_toMeMessageList().add(pwErrorMsg);
 //					client.getLst_toAllMessageList().add(pwErrorMsg);
 																}
@@ -1546,6 +1466,10 @@ public class MessageBusManagementThread extends Thread {
 //				this.client.disconnect();
 															}
 
+															else if (splittedMessageLine[0].equals("DE")) {
+																// DXCluster delimiter/end marker; intentionally ignored.
+															}
+
 															else {
 
 //				bufwrtrDBGMSGOut.write(new Utils4KST().time_generateCurrentMMDDhhmmTimeString()
@@ -1751,6 +1675,10 @@ public class MessageBusManagementThread extends Thread {
 					} catch (SQLException e) {
 						System.out.println("MsgBusMgt: process23001 went wrong / SQL Error");
 						e.printStackTrace();
+					} catch (RuntimeException e) {
+						System.out.println("MsgBusMgt: process23001 went wrong / Runtime Error while processing: "
+								+ messageTextRaw.getMessageText());
+						e.printStackTrace();
 					}
 				}