If that exists, it will be where the layout is stored. Deleting that should make it recreate the layout and hopefully your game project will load again.
I had a secondary issue where my recent project upgrade to 4.7.2 didn’t stick until I opened the uproject file through the launcher rather than by clicking on it directly.
So far 4.7.2 seems much more stable, but I’m having some launch issues on iPhone (runs on MAC). I think this might be because my project name has an _ in it but trying to confirm. I can build and launch TappyChicken, but still suck playing it. New thread later if I need help…