Weird exception when working on editor window: any idea why?

Questions & Answers
1

I have this weird exception popping when I enter a text in a text field (it’s supposed to fill a scroll view with related info then).

I am unable to track the origin of the exception: any idea what it could be?

NullReferenceException: Object reference not set to an instance of an object
UnityEngine.GUIScrollGroup.CalcHeight () (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/LayoutGroup.cs:733)
UnityEngine.GUILayoutGroup.CalcHeight () (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/LayoutGroup.cs:448)
UnityEngine.GUILayoutGroup.CalcHeight () (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/LayoutGroup.cs:402)
UnityEngine.GUILayoutGroup.CalcHeight () (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/LayoutGroup.cs:402)
UnityEngine.GUILayoutUtility.LayoutSingleGroup (UnityEngine.GUILayoutGroup i) (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/GUILayoutUtility.cs:251)
UnityEngine.GUILayoutUtility.LayoutFreeGroup (UnityEngine.GUILayoutGroup toplevel) (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/GUILayoutUtility.cs:227)
UnityEngine.GUILayoutUtility.LayoutFromContainer (Single w, Single h) (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/GUILayoutUtility.cs:190)
UnityEngine.Experimental.UIElements.UIElementsUtility.EndContainerGUI () (at C:/buildslave/unity/build/Runtime/UIElements/Managed/UIElementsUtility.cs:164)
UnityEngine.Experimental.UIElements.IMGUIContainer.DoOnGUI (UnityEngine.Event evt) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/IMGUIContainer.cs:272)
UnityEngine.Experimental.UIElements.IMGUIContainer.HandleIMGUIEvent (UnityEngine.Event e) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/IMGUIContainer.cs:335)
UnityEngine.Experimental.UIElements.IMGUIContainer.HandleEvent (UnityEngine.Experimental.UIElements.EventBase evt) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/IMGUIContainer.cs:322)
UnityEngine.Experimental.UIElements.EventDispatcher.PropagateEvent (UnityEngine.Experimental.UIElements.EventBase evt) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/EventDispatcher.cs:459)
UnityEngine.Experimental.UIElements.EventDispatcher.DispatchEvent (UnityEngine.Experimental.UIElements.EventBase evt, IPanel panel) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/EventDispatcher.cs:340)
UnityEngine.Experimental.UIElements.UIElementsUtility.DoDispatch (UnityEngine.Experimental.UIElements.BaseVisualElementPanel panel) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/UIElementsUtility.cs:251)
UnityEngine.Experimental.UIElements.UIElementsUtility.ProcessEvent (Int32 instanceID, IntPtr nativeEventPtr) (at C:/buildslave/unity/build/Runtime/UIElements/Managed/UIElementsUtility.cs:78)
UnityEngine.GUIUtility.ProcessEvent (Int32 instanceID, IntPtr nativeEventPtr) (at C:/buildslave/unity/build/Runtime/IMGUI/Managed/GUIUtility.cs:175)
2

I don’t know if you are still looking for answer but I had the same problem but it turned out I was calling EditorGUILayout.EndHorizontal() but I never began it. Hope this helps.