Originally posted by Nascarman:

you don’t need a mod to type /save so idk why one would exist

The command "save" only works when you are the host of the session, so you WOULD need a mod to bypass this restriction when playing on a dedicated server (but only if the server allows mods).

@OP Also, world save =/= character save, so it probably won't do you any good either way.

Had a lot of crashing going on too, so it's probably more feasible to just use the console and spawn the things you lost.