OS X Lion: FaceTime - There was an error processing registration when signing in
Symptoms
When you open FaceTime and try to sign in using your Apple ID, "There was an error processing registration" may appear with a message to try again later.
Products Affected
FaceTime for Mac, OS X Lion
Resolution
If third-party firewall software is installed, it needs to be configured to allow connections from apple.com and verisign.com.
If you have edited your /private/etc/hosts file, you will need to remove or comment out any entries containing apple.com or verisign.com.