Couldn't find anything related, so here goes:
In the game I'm working on, I started experiencing an error where it pop ups a warning "could not save resource". I then proceed to close and reopen StencylWorks, only to find a random actor erased from my game. If I try to create a resource with the same name, it marks the name as already being used. I've lost 3 actors so far, but nothing I couldn't redo easily. Still, it's annoying, and some actor's will be a major pain to recreate if this bug happens with them.
I redownloaded a fresh build about 4 days ago, and I started experiencing this yesterday.