Prefabs get broken randomly in Unity 2018.3

Sometimes i try to save a scene after making changes to it, items assigned to my prefabs go missing, and some prefabs cannot be selected or opened at all. They crash the Unity Editor. (I've sent a bug report).

I know i'm not the only one experiencing this. It looks like something's wrong with the fileID's of the prefabs. I've done my best to find the differences between a working prefab and a broken one by opening the .prefab file in a text editor.

I have attached the 2 prefab files in .txt format. One working and other one is broken. (Both prefab files have same components & child objects). Please see for yourself and help me find any differences..