My variables disappeared and appear back when I create new ones. Bug or something else?

My project started crashing this morning due to missing variables which were there before, it seems it applies only to Widget blueprints and the UI elements are gone but if I create a new variable, they appear back only to crash the whole editor when I click compile.

Not sure how best I described what’s happening, but here’s a video showing the process 2018-04-23_2224

Is there a way to fix this?