Unity UI 5.2 suddenly very glitchy

I have a project I've been working on for a while. Now I've just updated it to Unity 5.2 (first .1 now .p4) and that has caused a deluge of glitchy errors within the UI. It looks as if the atlassing does some weird things.

View attachment 158963

I've tried multiple versions of the project, some that worked when I built them just a few days ago in an earlier unity version and nothing has changed in them since. So it must be the Unity version. Unfortunately I get no error messages...

Unity UI 5.2 suddenly very glitchy