Yashica FX-D Quartz Door catch

I know this might sound too simple, but look to see if there's any old skin/covering or glue gunk that got stuck somewhere and it's preventing the door from fully closing - or - it's stuck to, or inside of, the door catch mechanism. The way those covers deteriorate and peel, it wouldn't be the first time parts of it went somewhere it shouldn't.

Other than that, it's sometimes an issue of bent prongs, or they get 'squished' or deformed from being forced. Look at everything as it's visible before popping things open. It may save a lot of work if you jump too far too fast. Exclude all the logical options before jumping into the inards.