Room save failed/got lost? Please help!

A friend of mine had been working on a map where he was only a mod, and he asked someone else to come save it which they did. Later on, we needed to load that save, but it was completely gone. it wasn’t under load saves and there was no backup either.

is this a glitch, or something else that anyone else has experienced, and can you do anything about it?

if the dude who saved it left the co-/owner/other role that allows you to save it might disappear. Otherwise iv got no idea