Program: 88449
Project: 88449
Buggy source:
@Override public void onMessage(Message message){
  if (isDisabled()) {
    return;
  }
  lastMessage=message;
  if (!(message instanceof TextMessage)) {
    return;
  }
  final String text;
  try {
    text=((TextMessage)message).getText();
  }
 catch (  JMSException e) {
    e.printStackTrace();
    return;
  }
  if (MDKOptionsGroup.getMDKOptions().isLogJson()) {
    System.out.println("String_Node_Str" + Converters.getIProjectToIdConverter().apply(project.getPrimaryProject()) + "String_Node_Str"+ System.lineSeparator()+ text);
  }
  JsonNode messageJsonNode;
  try {
    messageJsonNode=JacksonUtils.getObjectMapper().readTree(text);
  }
 catch (  IOException e) {
    e.printStackTrace();
    return;
  }
  if (!messageJsonNode.isObject()) {
    return;
  }
  JsonNode refsJsonNode=messageJsonNode.get("String_Node_Str");
  JsonNode syncedJsonNode=messageJsonNode.get("String_Node_Str");
  if (refsJsonNode != null && refsJsonNode.isObject()) {
    for (    Map.Entry<String,Changelog.ChangeType> entry : CHANGE_MAPPING.entrySet()) {
      JsonNode changeJsonNode=refsJsonNode.get(entry.getKey());
      if (changeJsonNode == null || !changeJsonNode.isArray()) {
        continue;
      }
      for (      JsonNode sysmlIdJsonNode : changeJsonNode) {
        if (!sysmlIdJsonNode.isTextual() || sysmlIdJsonNode.asText().isEmpty()) {
          continue;
        }
        String id=sysmlIdJsonNode.asText();
        try {
          ObjectNode elementJsonNode=JacksonUtils.getObjectMapper().createObjectNode();
          elementJsonNode.put(MDKConstants.ID_KEY,id);
          if (EMFImporter.PreProcessor.SYSML_ID_VALIDATION.getFunction().apply(elementJsonNode,project,false,project.getPrimaryModel()) == null) {
            continue;
          }
        }
 catch (        ImportException ignored) {
          continue;
        }
        inMemoryJMSChangelog.addChange(id,null,entry.getValue());
      }
      SyncStatusConfigurator.getSyncStatusAction().update();
    }
  }
 else   if (syncedJsonNode != null && syncedJsonNode.isObject()) {
    JsonNode sourceJsonNode;
    if ((sourceJsonNode=messageJsonNode.get("String_Node_Str")) != null && sourceJsonNode.isTextual() && sourceJsonNode.asText().startsWith("String_Node_Str")) {
      return;
    }
    Changelog<String,Void> syncedChangelog=SyncElements.buildChangelog((ObjectNode)syncedJsonNode);
    if (syncedChangelog.isEmpty()) {
      return;
    }
    Collection<String> ignoredIds;
    if (project.isRemote()) {
      ignoredIds=new HashSet<>();
      Collection<Element> locks=EsiUtils.getLockService(project).getLockedByMe();
      for (      Element lock : locks) {
        ignoredIds.add(lock.getLocalID());
      }
    }
 else {
      ignoredIds=Collections.emptyList();
    }
    for (    Changelog.ChangeType changeType : Changelog.ChangeType.values()) {
      Map<String,ObjectNode> inMemoryJMSChanges=inMemoryJMSChangelog.get(changeType);
      Set<String> keys=syncedChangelog.get(changeType).keySet();
      keys.removeAll(ignoredIds);
      keys.forEach(inMemoryJMSChanges::remove);
    }
    int size=syncedChangelog.flattenedSize();
    if (MDUtils.isDeveloperMode()) {
      Application.getInstance().getGUILog().log("String_Node_Str" + project.getName() + "String_Node_Str"+ size+ "String_Node_Str"+ (size != 1 ? "String_Node_Str" : "String_Node_Str")+ "String_Node_Str");
    }
    SyncStatusConfigurator.getSyncStatusAction().update();
  }
}

Fixed version (ground truth):
@Override public void onMessage(Message message){
  if (isDisabled()) {
    return;
  }
  lastMessage=message;
  if (!(message instanceof TextMessage)) {
    return;
  }
  final String text;
  try {
    text=((TextMessage)message).getText();
  }
 catch (  JMSException e) {
    e.printStackTrace();
    return;
  }
  if (MDKOptionsGroup.getMDKOptions().isLogJson()) {
    System.out.println("String_Node_Str" + Converters.getIProjectToIdConverter().apply(project.getPrimaryProject()) + "String_Node_Str"+ System.lineSeparator()+ text);
  }
  JsonNode messageJsonNode;
  try {
    messageJsonNode=JacksonUtils.getObjectMapper().readTree(text);
  }
 catch (  IOException e) {
    e.printStackTrace();
    return;
  }
  if (!messageJsonNode.isObject()) {
    return;
  }
  JsonNode refsJsonNode=messageJsonNode.get("String_Node_Str");
  JsonNode syncedJsonNode=messageJsonNode.get("String_Node_Str");
  if (refsJsonNode != null && refsJsonNode.isObject()) {
    for (    Map.Entry<String,Changelog.ChangeType> entry : CHANGE_MAPPING.entrySet()) {
      JsonNode changeJsonNode=refsJsonNode.get(entry.getKey());
      if (changeJsonNode == null || !changeJsonNode.isArray()) {
        continue;
      }
      for (      JsonNode sysmlIdJsonNode : changeJsonNode) {
        if (!sysmlIdJsonNode.isTextual() || sysmlIdJsonNode.asText().isEmpty()) {
          continue;
        }
        String id=sysmlIdJsonNode.asText();
        try {
          ObjectNode elementJsonNode=JacksonUtils.getObjectMapper().createObjectNode();
          elementJsonNode.put(MDKConstants.ID_KEY,id);
          if (EMFImporter.PreProcessor.SYSML_ID_VALIDATION.getFunction().apply(elementJsonNode,project,false,project.getPrimaryModel()) == null) {
            continue;
          }
        }
 catch (        ImportException ignored) {
          continue;
        }
        inMemoryJMSChangelog.addChange(id,null,entry.getValue());
      }
      SyncStatusConfigurator.getSyncStatusAction().update();
    }
  }
 else   if (syncedJsonNode != null && syncedJsonNode.isObject()) {
    JsonNode senderJsonNode;
    if ((senderJsonNode=syncedJsonNode.get("String_Node_Str")) != null && senderJsonNode.isTextual() && senderJsonNode.asText().equals(TicketUtils.getUsername(project))) {
      return;
    }
    Changelog<String,Void> syncedChangelog=SyncElements.buildChangelog((ObjectNode)syncedJsonNode);
    if (syncedChangelog.isEmpty()) {
      return;
    }
    Collection<String> ignoredIds;
    if (project.isRemote()) {
      ignoredIds=new HashSet<>();
      Collection<Element> locks=EsiUtils.getLockService(project).getLockedByMe();
      for (      Element lock : locks) {
        ignoredIds.add(lock.getLocalID());
      }
    }
 else {
      ignoredIds=Collections.emptyList();
    }
    for (    Changelog.ChangeType changeType : Changelog.ChangeType.values()) {
      Map<String,ObjectNode> inMemoryJMSChanges=inMemoryJMSChangelog.get(changeType);
      Set<String> keys=syncedChangelog.get(changeType).keySet();
      keys.removeAll(ignoredIds);
      keys.forEach(inMemoryJMSChanges::remove);
    }
    int size=syncedChangelog.flattenedSize();
    if (MDUtils.isDeveloperMode()) {
      Application.getInstance().getGUILog().log("String_Node_Str" + project.getName() + "String_Node_Str"+ size+ "String_Node_Str"+ (size != 1 ? "String_Node_Str" : "String_Node_Str")+ "String_Node_Str");
    }
    SyncStatusConfigurator.getSyncStatusAction().update();
  }
}