NullRef Caret

NullReferenceException: Object reference not set to an instance of an object
FGTextBuffer+CaretPos.op_LessThan (.CaretPos A, .CaretPos B) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextBuffer.cs:252)
FGTextBuffer.GetTextRange (.CaretPos from, .CaretPos to) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextBuffer.cs:756)
FGTextEditor.ProcessEditorMouse (Single margin, UnityEngine.Event current) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextEditor.cs:2323)
FGTextEditor.DoGUI (Boolean enableGUI) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextEditor.cs:1945)
FGTextEditor.DoGUIWithAutocomplete (Boolean enableGUI) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextEditor.cs:1202)
FGTextEditor.OnWindowGUI (UnityEditor.EditorWindow window, Boolean isTextInspector) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextEditor.cs:1104)
FGTextEditor.OnWindowGUI (UnityEditor.EditorWindow window) (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGTextEditor.cs:1005)
FGCodeWindow.OnGUI () (at Assets/FlipbookGames/ScriptInspector2/Editor/Scripts/FGCodeWindow.cs:686)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Applications/buildAgent/work/b59ae78cff80e584/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)