The latest version of iTunes just managed to throw away my entire stash of playlists whilst syncing with my iPhone. I've tried reimporting the .xml and .itl files, I've tried restoring older backups of those files, but nothing. Not only that, it's also forgotten I have all my tunes etc. on my hard drive, and thinks they're all in a cloud somewhere. So I'm reimporting the tunes into the library from where iTunes put them in the first place (having been careful to turn off the option to copy them into the iTunes folders!) - I have some vague hope that once they're officially all there again, it'll let me restore the playlists too.

If not, that represents a decade of playlists I'll never be able to recreate from memory.

Move the whole current iTunes folder out of the music folder, and copy a backup to there. Launch iTunes while holding down the option key, and point it to the backup library you just copied over.

Tried all that too, sadly no dice. It's a real mystery.

Back up?

Embarrassing (but also annoying) conclusion to this tale of woe - it turned out that my playlists were not lost, but merely "hidden". I discovered this quite by accident, because in the new iTunes design, the hide/show "button" is only visible if your cursor is directly over it (so I'd had no idea that the possibility of hiding your entire stock of playlists was a possibility). I've restored from a day-old backup and all is well.

Oops. Also if you go to the menu bar under View there is an option to Show Sidebar.

Does anyone know why this happens? It seems like this "damaged" thingie showed upon not quite two years ago and hasn't quit.

iTunes never used to crash or do stupid things for me, but the last two years are making me think about getting a new player.

Also, thanks to all who've commented on the flaws with Mavericks. I bought a Mac Mini the other day but haven't set it up yet. I was going to install Mavericks right away, but I think I'll hold off for now.

Mavericks is 99% fine. It's the 1% use case that's a real problem for people in the design/content creation business. Unfortunately, the amount of headache caused by the 1% is fairly substantial.

Hmmm, I was a 1%-er, but I did't feel super-wealthy...

'And now that I'm back to Mt. Lion, I'm no richer, but at least my app's aren't broke! *rim shot* Hey, I'm here all week.

I know you mentioned it before, but what apps were "broke?" I know we talked about Adobe CC - which I also have several issues with. It's funny, but CS6 runs pretty good on Mavericks - way better than CC. But I don't have a non-Mavericks Mac to test CC on to see if the problem is indeed Mavericks, or if it's just an Adobe issue with a new version.