Last week was a fairly big one for the iPhone stack, what with the release of iTunes 10.2.1 and subsequent release of iOS 4.3. Of course, I dutifully installed both. A fairly painless, if long-winded exercise.
I noticed a couple of days later a problem syncing my phone with my MacBook Pro. On connection of the phone, iTunes displayed the following error message:
iTunes was unable to load dataclass information from Sync Services. Reconnect or try again later.
Well, I did and the same message was displayed next time. So, I rebooted the MacBook Pro and, for good measure, rebooted the iPhone too. On connecting the phone (once iTunes had started up) - no change. Same message.
On closer inspection, it looked as though the phone was actually syncing but not backing up. Not a situation that I was happy with, so time to start investigating seriously. After much trawling of the usual haunts (starting with my search engine of choice, naturally), I uncovered both the cause and the fix, though the relationship between them isn't especially obvious. While I supposed that the issue lay with either iTunes 10.2.1 or iOS 4.3, there was another little detail that I hadn't noticed (and have thus far neglected to mention). Shortly after these upgrades, Apple posted the latest version of XCode to the Mac App Store. Despite not yet having built a real iOS application in anger, I couldn't not have it, so I clicked the button, entered my Apple password and let XCode install. It was XCode, it appears, that was the root of my synchronisation issues. The connection may seem tenuous, but I suspect it could well be related to the inclusion of the iPhone emulator replacing important files.
The solution was found on Apple's support site, here: iTunes: How to remove and reinstall the Apple Mobile Device Service on Mac OS X
Basically, it involves uninstalling iTunes, removing two Apple Mobile Device Service files and reinstalling iTunes. You'll be especially pleased to know, if you have to go through this process yourself, that all of your iTunes content and configuration remains unharmed.
Mar 14 2011, 02:57 PM