sync session failed to start

Neither my phone nor iPad would sync suddnely. Once I deleted just the last back up for my iPhone, both now sync perfectly! I have an iMac, so did not worry about deleting the sync history, as that was not an option offered to me. Thanks to all of you helpful folks that post solutions!! 🙂

Here's what worked for me:

1. In iTunes: Edit ==> preferences ==> Devices

2. Select listed backup

3. [Delete backup]

4. [Reset Sync History] (For some reason the button remains active and there is no indication it worked.)

5. Try to manually Re-Sync

A. This did not work for me. But eject the device (iPhone for me)

B. Do not unplug your device.

C. Close and then reopen iTunes.

D. Re-Sync manually.

This worked for me.

Thank you Pablokimon. That did the trick!

Here is the best QUICK trick to resolve this problem : http://www.youtube.com/watch?v=vgd6P1VRfe8

I encounter this problem after I installed iOS 6.0.1 on my iPhone 4S. Thanks to this forum, deleting the back ups resolved the problem. Thank you very much.

However, I noticed that for some strange reason, one of the recent updates to the iPhone has deleted all the 35GB of music that I stored on the iPhone. Yes it can be accessed by the iCloud, but when I am at the gym or in the mountains, I have no access to AT&T or to a WiFi connection. That is why I had it on the phone in the first place. I got no warning, they just erased it.

As anyone else noticed that Apple software is beginning to have the same reliability as Microsoft. Hey guys, if the software is buggy, do not release it. That is why I switched to Apple. Now Siri is buggy, Maps are buggy. iOS new release is buggy. Is Apple now willing to release software that doesn't work or is pooly tested?

Mr. Cook, you better get your collective crap together and so you don't become a second class Microsoft.

Thanks E.L.W., this worked for me!

I have a similar configuation to a lot of people having this problem - Win 7 64bit, Norton Security/Firewall, iTunes 10.7. I tried many of the suggested solutions without success. What finally worked for me was really pretty simple, borrowing bits and pieces of potential fixes discussed by other users. I disconnected both my iPhone and iPad from the PC, put them in Airplane Mode, and them rebooted both of them. I then rebooted the PC. With a fresh reboot on the PC, I used the Task Manager to shutdown every process and program that looked like it might be Apple related. I then went through Control Panel to uninstall every program with Apple as the publisher. I also deleted the Apple Lockdown folder. I rebooted my PC (with the Apple components removed). After the restart, I did a clean install of iTunes 10.7. After that install, when all that was done I rebooted by PC again.

At this point I tried iTunes and started without any problems. I then, one at a time, took my iPhone and iPad off Airplane mode, and attached them to the PC via USB with iTunes running. They both synced and backed up without incident. I tried them again the next day, and the sync and back up processes are still working fine. I just hope that this solution sticks.

I solved this by moving files off the drive which I use for itunes. Previously there was 5GB free, but the backups are larger. Plus I think it must need space to cache the new backup before replacing the old one.

Just did what ambs92 suggested - worked like a charm! Immediately did the normal sync. Thanks so much! Never had it happen before. I have the iPhone 4s. Will remember in case it happens again. Has made my morning look much brighter! 🙂

Pablokimon has it right. Open iTunes > Preferences > Devices, delete the iPhone backup(s), close and restart iTunes and then start Sync.

It's a less than 5 minute fix.

Thanks Pablo.

Thanks - this worked for me.

I just had the same problem, and before deleting back ups, I closed and restarted itunes. Phone synced right away.

I was getting the same error. The iPhone "iPhone" could not be synced because the sync session failed to start.

I've seen many suggest deleteing backups, but I saw no such option available. I'm using iTunes 11.0.0.163 for Windows 7 (64bit).

File>Devices> shows only these options:

Sync "iPhone"

Transfer purchases from "iPhone"

Backup

Restore from backup...

Where are people seeing Delete backup?

After further research in the forum, I saw where some found setting iTunes to Run as Administrator helped.

This is what I did and it fixed the problem completely:

1) closed iTunes

2) configured iTunes to Run as Administrator

3) unplugged the iPhone from USB

4) plugged iPhone into USB

Windows automatically launched iTunes and began syncing.

The phone now syncs fine.

Happy dance.

I do understand no solution will work for everybody but I must thank those of you who suggested "deleting backup".

My device is a generation one ipad operating on oss 5.1.1, my computer is an imac snow leopard. Like most every one else I could not find a "reset sync" but once I deleted backup and restarted my pad, things began to work.

Thank you, everyone who responded

This worked perfectly, thanks.