I don’t know how often this happens to others but it happened to me. I just downloaded a video file to iTunes and was about to sync it to my iPhone when the dialog box above popped up.
It doesn’t have anything to do with the video file I’m trying to sync but I know I still have applications that haven’t been synced between iTunes and iPhone. I’m not sure either if this was caused by the new iTunes version (8.1.1) that I installed a few days earlier.
Anyway, I thought I just have to authorize my computer again and everything will be okay. Nope. iTunes says my computer is already authorized.
Syncing again only brings back the same pop-up messages. Deauthorizing and authorizing again didn’t work.
Apple Support suggests this solution:
It also mentions deleting the SC Info folder.
Unfortunately, it didn’t solve my problem.
It gets frustrating until finally I found a solution.
- Deauthorize your computer in iTunes (from the Store menu).
- Sign out from your iTunes Store account.
- Quit iTunes and unplug your iPhone.
- Remove the “iTunes Helper” application from the Startup items (In Mac, go to System Preferences -> Accounts -> Login Items)
- Delete/uninstall the iTunes application (this won’t erase your iTunes media files).
- Download iTunes from the Apple website and install.
- Start iTunes and sign in to the iTunes Store.
- Authorize your computer (from the Store menu).
- Plug in your iPhone and Sync!
Hope this solution works for you too.