The iPhone "..." could not be synced because the sync session failed to start

Thanks for the tips FL - unfortunately - no luck. Was already on the latest everything (no betas), did the trash emptying and disbaled icloud. Can't say I know how to do an icloud sync?

Anyway, after trying everything, I did a full erase/restore with the latest 5.1 beta and then a backup restore to a backup about a month ago just in case to avoid corruption in a backup. All is well... FINALLY!!

I am going to keep my wifes iphone 4 broken so when apple gets back to me on the bug I submitted, maybe they can get to the bottom of this.

Regarding the iCloud, you have to enable the iCloud and not disable it. If you disabled it you have to reactivate it and recreate the account. Then either sync up to the Cloud with your device or iTunes. You can do this after installing the new software update. After you install the update on your device, your device will ask you if you want to use the Cloud or not. You can also control the iCloud settings under Settings | iCloud like I said above.

After you sync with the Cloud and everything goes well, then change it back to the USB option but you must complete the sync with the Cloud if you messed around with the settings.

Also enable the option in iTunes to sync via Wifi.

The problem seems to involve the Trash and the iCloud via Wifi.

Although someone mentioned about Outlook mail, I did not do anything with my Outlook mail.

Look in Settings | iCloud carefully.

Did anyone try restarting your computer? it worked for me 🙂

I don't have any beta versions of software on my iPhone 4 and cannot sync for the same reason of the original post

I'm having the same issue. I have no Beta versions of anything on my iPhone, iPad, or MacBook but I can't sync either device due to this error

I tried this restore solution and it worked for me too. Took three hours to reload the back-up but got there in the end. Naughty Apple "upgrades" !!

for me, my backup setting in Summary in itunes was setup to icloud instead of my computer and since i hadnt set up icloud, that was the issue

once i switched it, it worked fine

have you tried quitting itunes and reopening it

I did everythig you said and it worked at first. I was able to upload 3-4 pics to my phone and then the same problem occured again. I'm using iTunes 10.5.2, any suggestions?

If you leave your iPhone plugged into your computer when you shut down and it is still plugged in when you restart, iTunes and the syncing software does not like it. Don't know why.

I have had good success when I start-up my computer without my iPhone attached.

Good luck & happy holidays.

What's this nonsense about beta 1 and beta 2 ?? .. could someone tell me what this means ? ...

I was able to get this working on OSX 10.7.2 and my iPhone 4S after restarting iTunes.

Would the updating to beta 2 solution work for an iPod Touch 4?

Have had this problem occassionally. I'm running iTunes 10.5.2(11) on OS X (MacBook Pro w/ Snow Leopard 10.6.8) and iOS 5.0.1 on an iPhone 4.

This fixed the problem:

1) Unplug the iPhone from the computer

2) Power down the iPhone and restart

3) Restart the computer

4) Plug the USB cable in

... it synced.

I think people that experience this problem fall into one of two categories:

1. Intermittent failures that are typically solved by restarting,etc.

2. People that can not start a sync despite the simple tips in this thread.

I was in the latter category. Until I did a clean restore of the entire device, I couldnt sync. Then sometimes minutes, sometimes days later, I would again not be able to sync, and no simple remedies worked. Only anothe full restore would allow syncing again.

I think I finally figured out my issue. I was also having a problem with itunes match. A number of people have seen a similar issue where empty playlists get duplicated thousands of times. I had 67,000 emoty playlists. Turns out they were all synced up to icloud, so even after a restore (as above), they would come back. I finally got rid of the playlists by using a script that deleted them one at a time (took like 8 hours). If you have this problem, once the script finishes, be sure to allow itunes to run for a while to syn all the local deletes to icloud. I made the mistake of not waiting long enough, and 5000 came back. After subsequently removing them cleanly, I hae not had any problems syning. Certainly could see why 60,000+ playlists might cause the sync process to vomit.

After a month of this nonsense, I am finally free of the playlists and syncing reliably.