NullReferenceException LayoutGroup since 2019.2.0.a4

Hey all! :D

Im super new to Unity and C#. I updated my Project to 2019.2.0.a4. I didnt know that i could be a big deal, and it wasnt! (but i wont do it again) Everything works find and still is except one thing. I always get this:

NullReferenceException: Object reference not set to an instance of an object UnityEngine.UI.HorizontalOrVerticalLayoutGroup.Update () (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Layout/HorizontalOrVerticalLayoutGroup.cs:266)

I dont know what it effects. It only occurs in the editor when im interacting with my Layoutgroups. I cant find any major bugs, besides sometimes resetting my Transform on it, but its also bit annoying. So anybody can help me out what i can do, or do i simply have to wait for the full release?

Thanks alot! Greetings