I upgraded to iTunes 11 and it destroyed my entire music library in one fell swoop.
After the upgrade to 11, many of my mp3 files got moved to Unknown Album folders. If I looked at the files in Windows Explorer, I could see the album name, track number, and track name still in the ID3 tags. Why iTunes couldn't read them at this point is a mystery.
After some searching around, I found that iTunes apparently has some trouble with differing ID3 tag versions, and some threads suggested converting them to a newer version. I started this process, and it went through without reporting any errors. However, the failure mode for tags it can't read is apparently to DELETE THE INFORMATION THAT IS THERE.
Is there any way I can get this information back, or any tools that might be helpful in getting this working again?
I'm running Windows 7.