Check null _tablecontrol for on events

Author: JoseGomis299

Assets/TableForge/Editor/UI/Windows/TableVisualizerWindow/TableVisualizer.cs

@@ -103,6 +103,8 @@ private void OnProjectChanged()
 
         private void OnScriptableObjectModified(ScriptableObject scriptableObject)
         {
+            if(_tableControl == null) return;
+            
             Row row = _tableControl.TableData.Rows.Values.FirstOrDefault(r => r.SerializedObject.RootObject == scriptableObject);
             if(row == null) return;
 
@@ -111,6 +113,7 @@ private void OnScriptableObjectModified(ScriptableObject scriptableObject)
 
         private void Update()
         {
+            if(_tableControl == null) return;
             if(!TableSettings.GetSettings().enablePolling || _lastUpdateTime >= EditorApplication.timeSinceStartup - TableSettings.GetSettings().pollingInterval)
                 return;