while i'm working on character's with ff sometimes i go to test what ive done by hitting the launch mugen icon (in ff). Mugen will sometimes lock up my cpu causing me to turn power off then back on. I have ended up with messed up sff files, as well as erased cmd & cns files. Literally losing an entire character this way, so back up your files just incase. Never had this problem with linux mugen though, maybe the hack of mugen that is winmugen created this problem?
Make backups, click on the lock next to the save button and it will create files such as
example.act.bak
example.cns.bak
example.sff.bak
example.snd.bak
These files are copies of your character's files at the time of which you backed them up. To make them work, remove .bak from the file names