Lost Project

When I last closed Studio 2019, I got an error message. Unfortunately I cannot remember what it said. Possibly something about "Cannot find path..." but I'm not sure if it was that. Somehow it closed in the end.

On opening again, my 70% completed project was not in the list. I searched in Projects file and a 33% complete version is there. I am not sure where the other one has gone. I definitely saved it in a more completed state.

Any help gratefully received.

Thank you