I just experienced this problem for the first time myself. Yesterday, I had well over 6,000 songs in iTunes; then, this morning when I tried to open up iTunes, I got hit with the same error and subsequent message: "‘iTunes library does not appear to be a valid iTunes library file. iTunes has attempted to recover your iTunes library and renamed this file to “iTunes Library (Damaged)". All my playlists were gone and over 3,000 songs were missing!! GOOD NEWS, though.... I figured out a solution that worked for me. Maybe it will work for you? I went into my iTunes data file folder on my computer. There, I noticed two files of particular relevance: 'iTunes Library' and 'iTunes Library (Damaged)'. I also noticed that the (new) iTunes Library folder was only 4.83MB, whereas the iTunes Library (Damaged) file was 26.1MB. It appears that iTunes created a new library DAT file once it determined that the original was corrupted. Now, I don't know why I got the error message (in question) in the first place. It could have been (and hopefully was) just a fluky glitch. But this is what I resolved to try... I created a new file folder named iTunes Library Backup Files; I then copied the two iTunes library DAT files--the new one and the damaged one--into this folder. I then went back out to the parent folder and deleted the new (created) 'iTunes Library' file and renamed the 'iTunes Library (Damaged)' file to 'iTunes Library'. This, apparently, is the file that iTunes will read and use whenever you open the app. Then, the next time I opened iTunes, I didn't get an error message and PRESTO... I had recovered all of my playlists and music files as if I had never had a problem to begin with. Now, this worked for me; it may not work for you all. But it's worth a shot, I suspect. Try it (if need be), and let me know if it works. Good Luck! --SM