I have tried tagging two specific files for an album and they refuse to work. I have checked every place they would possibly be in. I've tried renaming the files, renaming it goes through fine, but the metadata refuses to change. I put songs of the same format in there too, and MP3Tag is fine with those, even though they're the same type. I am very confused. I tried to change it via Windows Properties itself, and it says its unable to do it. I've checked and I do have permissions to edit the file, it just refuses to edit. I've also tried opening it in music players and they process it fine, so it isn't corrupt either.
What kind of files are these? WAV? MP3? FLAC?
Have you tried checking the problematic files?