It will do it at random, of the three times I tried to use the editor it happened every time, and I lost all my work My only guess i think is that twice it happened when i pressed s while in the move object tool, cant force it to happen really though and id rather not keep trying to see.
Other issues:
Menus bug out in the editor a bit where they dont open/close when they should so i have to open/close them again to refresh it, sometimes and its a small annoyance
My friends game only opens if he closes it in task manager (no idea)