I'm using an iPhone 4 running iOS 4.3.5. Tried to install iOS 5, but received the following error after about 5 minutes attempting to back up: Of course, I don't want that. The phone has never had upgrade problems before and it's never been jailbroken. Any ideas? Mac is running 10.7.2 and iTunes 10.5. iTunes is set up for encrypted backups. I tried turning off the encrypted backup as well as deleting the backup and letting the upgrade process create it. Nothing helps! I should note that I can create a manual backup without problems and it syncs fine. I had posted this over at Apple's discussion forum, but their site is running super slow at the moment. Edited to add: We're getting somewhere. I had my MobileSync folder symlinked to my HDD to keep it off my SSD. I moved it back to the SSD and the backup portion of the iOS 5 upgrade worked. Now I'm getting this error: After doing the backup, the iOS 5 upgrade goes through "Extracting software" and finally "verifying iPhone restore with Apple." It's during that last message that the internal error occurs. Reading over at Apple's forums suggests that this is an issue with Apple's servers getting hammered right now and after 5 or so attempts it finally upgraded for them. I'll just keep at it. This iOS upgrade has been the worst Apple upgrade I've ever experienced, which is a good thing, because it doesn't happen a lot, but still. This sucks! Second Update: Looks like I got past the verification step and it's proceeding with the upgrade. Yay!