Thanks for the answer Nick! 
So when should I sent you the project? Once the REINST bug appears which is not fixable by compiling everything again manually?
I don’t think I’m doing anything special what you don’t have in your own “test beds”. I just often directly reference the parent widget in the child widget. Are all problems you have in your test bed fixed, so do you not have any projects there where REINST problems appear which are not fixed by compiling all widgets? If you already have a project where you can reproduce this, I don’t need to upload my whole 20GB project :rolleyes:
When I first started up my project today/yesterday I actually noticed that one widget again was changed to REINST and it was not fixable by compiling anything. So I again had to delete it and so on. And even worse, even if I get everything to work again in the editor, while packaging it seems to change again to REINST or for any strange reason all wires to references of this widget get cut and packaging fails, I also wrote a bug report about this today/yesterday on the answerhub: Nodes disconnecting while packaging, packaging fails - UI - Unreal Engine Forums
It’s a bit “unpleasant” to not be able to package the project…
As for the non-UMG cyclical dependency problems which only occur in one of my actors, I already wrote a bug report about this on the answerhub in June and Samantha Sutton was able to reproduce the issue, it’s UE-17866 but she said it’s set as a “minor bug” so I guess it’s not important for you to fix it.