I've been using mp3tag for quite a while, without issues, and use it almost exclusively to manage music file tags on my computer. Unfortunately, this last revision seems to be causing me a few problems with FLAC files.
When selecting several of them at once, such as those of an entire album, I was attempting to add covers and make sure Album titles are spelled the same way on all files of the same album. I made the desired changes and pressed the save button, and after 5 or 6 flies got processed without issue, a message popped up saying the tags could not be written to the file with an option to Cancel or Ignore, if I recall correctly. (While unusual, this is not in and of itself too worry to me, since it can normally be caused by having the file open and playing, or having the antivirus scanning to my media, for example.) However, the FLAC file in question will not be restored to it's original state regardless of the choice picked. MP3TAG display will update to indicate all flags were deleted from the affected file, so it will seem as an inconvenience, requiring just a complete tag re-write for the file(s) in question, but the truth is the file will be deleted instead.
If I stop the process right there by selecting cancel, I can recover the FLAC as a .tmp file in the directory affected, but if I press Ignore, the .tmp will also be gone, and the original FLAC will be lost. If it occurs again in the same directory, a .tmp of the last affected file will remain, but not one of the first file.
I had it happen 4 times on three different directories, (fortunately I only lost one file, and I intend to scourge the net later to replace it,) but I'm a little weary of attempting to replicate this bug again to get more info. I might just re-install the previous version later, as I did not have any issues previously...
Also, This bug does not seem to affect mp3 files, as I also updated a few mp3 albums without incident in the same session.
Thank you for producing (and maintaining) an incredibly useful application that's made managing music collections so much easier for tons of people! hopefully this is not a widespread bug, and just a problem for a handful of people. (Because I don't want it to be a widespread bug for everyone, or a peculiarity of my own particular hardware/software installation giving me problems...)