Some users have reported an issue in which videos purchased from the iTunes store will not play properly after the update to iTunes 9.2, displaying only a gray screen. In many cases, users are asked for authorization when attempting to play these videos, only to receive a message stating that the computer is already authorized.
Delete SC Info folder. Try deleting the SC Info folder as described in this Apple Knowledge Base article.
Downgrade to iTunes 9.1.1. Although this solution is far from ideal, and will result in the elimination of security and feature enhancements in the iTunes 9.2 update, it may restore the ability to watch videos purchased through the iTunes store.
If you have a Time Machine backup, simply use it to restore your iTunes 9.1.1. Otherwise, follow these instructions:
First, delete the following files
- The iTunes application in /Applications
- com.apple.iTunes.plist, which is located in ~/Library/Preferences (this is the library folder inside your user folder)
- iTunes.pkg, which is located in /Library/Receipts (this is the library folder at the root level of your startup drive)
- iTunesX.pkg, which is located in /Library/Receipts
Next, download iTunes 9.1.1 and install it.
You may then need to recreate your iTunes library.