fixed IDE crashing when detaching editor

Author: maxijabase

UI/Components/EditorElement.xaml.cs

@@ -736,7 +736,7 @@ private void ParseIncludes(object sender, EventArgs e)
 
                 var caret = -1;
 
-                if (ee == null) return;
+                if (ee == null || ce == null) return;
 
                 var definitions = new SMDefinition[ee.Length];
                 List<SMFunction> currentFunctions = null;