I upgraded an application that I had developed in 7.9 where I had buttons on the screen and since that point all of the buttons seem to have lost their definition and you can’t see them anymore. All I have is text on the window where the button is, no definition of the button and no click animation.
I have tried creating new buttons and moving the functionality over but after saving the screen and re-opening it the definition is gone again.
Yes, this is a known issue (I'm working on fixing it right now, fix should be in sometime next week). In the meantime, I would plan on re-importing your windows from the previous project after the fix is in - anything you've saved in the beta so far will probably not keep the styling properties you want.