I just downloaded and installed the 4.3 preview build, but once I opened up my project (after copying and converting) it opens up an example map (but still has all my assets in CB) but none of the file menu buttons do anything? If you click on one, the window goes out of the windows focus (as if another window came up) and if you click on it again it focuses it again, I’ve restarted windows, reinstalled 4.3, nothing works? Does anyone have a fix?
Thanks 
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Thank you.
Posting second answer, first one did not work due to bug in system.