Program: 143477
Project: 143477
Buggy source:
/** 
 * @param message
 */
public void handleMessage(final JSONObject obj){
  startHandlingEvent();
  if (client != null)   J2DBGlobals.setServiceProvider(client);
  try {
    String event=obj.getString("String_Node_Str");
switch (event) {
case "String_Node_Str":
{
        pushChanges(obj,false);
        break;
      }
case "String_Node_Str":
{
      pushChanges(obj,true);
      break;
    }
case "String_Node_Str":
{
    getEventDispatcher().addEvent(new Runnable(){
      @Override public void run(){
        try {
          JSONArray jsargs=obj.getJSONArray("String_Node_Str");
          IWebFormUI form=client.getFormManager().getFormAndSetCurrentWindow(obj.getString("String_Node_Str")).getFormUI();
          WebFormComponent webComponent=form.getWebComponent(obj.getString("String_Node_Str"));
          String eventType=obj.getString("String_Node_Str");
          Object[] args=new Object[jsargs == null ? 0 : jsargs.length()];
          for (int i=0; jsargs != null && i < jsargs.length(); i++) {
            args[i]=jsargs.get(i);
          }
          String error=null;
          Object result=null;
          if (form instanceof WebGridFormUI && obj.has("String_Node_Str") && !((WebGridFormUI)form).setEditingRowByPkHash(obj.getString("String_Node_Str"))) {
            error="String_Node_Str" + obj.getString("String_Node_Str");
          }
 else {
            pushChanges(obj);
            try {
              result=webComponent.executeEvent(eventType,args);
            }
 catch (            Exception e) {
              Debug.error(e);
              error=e.getMessage();
            }
          }
          if (obj.has("String_Node_Str")) {
            WebsocketEndpoint.get().sendResponse(obj.get("String_Node_Str"),error == null ? result : error,error == null,getForJsonConverter());
          }
        }
 catch (        JSONException|IOException e) {
          Debug.error(e);
          sendInternalError(e);
        }
      }
    }
);
    break;
  }
case "String_Node_Str":
{
  String formName=obj.getString("String_Node_Str");
  IWebFormUI form=client.getFormManager().getForm(formName).getFormUI();
  WebFormComponent webComponent=form.getWebComponent(obj.getString("String_Node_Str"));
  Object property=webComponent.getProperty(obj.getString("String_Node_Str"));
  LookupListModel lstModel=null;
  if (property instanceof CustomValueList) {
    lstModel=new LookupListModel(client,(CustomValueList)property);
    webComponent.setProperty(obj.getString("String_Node_Str"),lstModel,ConversionLocation.BROWSER_UPDATE);
  }
 else   if (property instanceof LookupValueList) {
    lstModel=new LookupListModel(client,(LookupValueList)property);
    webComponent.setProperty(obj.getString("String_Node_Str"),lstModel,ConversionLocation.BROWSER_UPDATE);
  }
 else   if (property instanceof LookupListModel) {
    lstModel=(LookupListModel)property;
  }
  if (lstModel != null) {
    lstModel.fill(null,null,obj.getString("String_Node_Str"),false);
  }
  break;
}
}
}
 catch (Exception e) {
Debug.error(e);
sendInternalError(e);
}
 finally {
stopHandlingEvent();
J2DBGlobals.setServiceProvider(null);
}
}

Fixed version (ground truth):
/** 
 * @param message
 */
public void handleMessage(final JSONObject obj){
  startHandlingEvent();
  if (client != null)   J2DBGlobals.setServiceProvider(client);
  try {
    String event=obj.getString("String_Node_Str");
switch (event) {
case "String_Node_Str":
{
        pushChanges(obj,false);
        break;
      }
case "String_Node_Str":
{
      pushChanges(obj,true);
      break;
    }
case "String_Node_Str":
{
    getEventDispatcher().addEvent(new Runnable(){
      @Override public void run(){
        try {
          JSONArray jsargs=obj.getJSONArray("String_Node_Str");
          IWebFormUI form=client.getFormManager().getFormAndSetCurrentWindow(obj.getString("String_Node_Str")).getFormUI();
          WebFormComponent webComponent=form.getWebComponent(obj.getString("String_Node_Str"));
          String eventType=obj.getString("String_Node_Str");
          Object[] args=new Object[jsargs == null ? 0 : jsargs.length()];
          for (int i=0; jsargs != null && i < jsargs.length(); i++) {
            args[i]=jsargs.get(i);
          }
          String error=null;
          Object result=null;
          if (form instanceof WebGridFormUI && obj.has("String_Node_Str") && !((WebGridFormUI)form).setEditingRowByPkHash(obj.getString("String_Node_Str"))) {
            error="String_Node_Str" + obj.getString("String_Node_Str");
          }
 else {
            pushChanges(obj);
            try {
              result=webComponent.executeEvent(eventType,args);
            }
 catch (            Exception e) {
              Debug.error(e);
              error=e.getMessage();
            }
          }
          if (obj.has("String_Node_Str")) {
            WebsocketEndpoint.get().sendResponse(obj.get("String_Node_Str"),error == null ? result : error,error == null,getForJsonConverter());
          }
        }
 catch (        JSONException|IOException e) {
          Debug.error(e);
          sendInternalError(e);
        }
      }
    }
);
    break;
  }
case "String_Node_Str":
{
  String formName=obj.getString("String_Node_Str");
  IWebFormUI form=client.getFormManager().getForm(formName).getFormUI();
  WebFormComponent webComponent=form.getWebComponent(obj.getString("String_Node_Str"));
  Object property=webComponent.getProperty(obj.getString("String_Node_Str"));
  LookupListModel lstModel=null;
  if (property instanceof CustomValueList) {
    lstModel=new LookupListModel(client,(CustomValueList)property);
    webComponent.setProperty(obj.getString("String_Node_Str"),lstModel,ConversionLocation.BROWSER_UPDATE);
  }
 else   if (property instanceof LookupValueList) {
    lstModel=new LookupListModel(client,(LookupValueList)property);
    webComponent.setProperty(obj.getString("String_Node_Str"),lstModel,ConversionLocation.BROWSER_UPDATE);
  }
 else   if (property instanceof LookupListModel) {
    lstModel=(LookupListModel)property;
  }
  if (lstModel != null) {
    lstModel.fill(null,null,obj.getString("String_Node_Str"),false);
  }
  break;
}
case "String_Node_Str":
formCreated(obj.getString("String_Node_Str"));
break;
}
}
 catch (Exception e) {
Debug.error(e);
sendInternalError(e);
}
 finally {
stopHandlingEvent();
J2DBGlobals.setServiceProvider(null);
}
}