"Lately I have been having problems syncing my iPhone with iTunes. The most recent error is 'Sync Session Failed to Start'. What's wrong with my iTunes? Is there any way to fix it?"
Occasionally, when you try to sync your iPhone, iPad or iPod with iTunes, it may prompt you that "The iPhone "iPhone" could not be synced because the sync session failed to start." Or "iTunes could not sync calendars to the iPhone "iPhone name" because a sync session could not be started?" This is strange and most of this is due to some unknown error in iTunes. Below we sum up several useful ways to help you fix "iTunes sync session failed to start" error.
With the help of TunesCare, you can repair all iTunes syncing issue for iDevices by fixing the corrupted iTunes library.
Step 1: Download, install and launch TunesCare on your PC, then connect your iOS device to computer with a USB cable.
Note: If TunesCare cannot detect your device, just click "Fix All iTunes Issues" to have your iTunes fixed.
Step 2: After TunesCare detected your device, hit "Fix iTunes Sync Problems" and then TunesCare will start the corrupted iTunes library repair.
Step 3:Once repair completed, you can open your iTunes and sync what you want normally.
Some users discussed on Apple Community shared this way which worked for them. Follow these steps to force an app to close:
After that do a Soft reset of your iPhone by holding both Home and Sleep button for around 10secs until you see the Apple logo then release. After it returns to Home screen, connect to sync and see if this resolves the issue.
If method above didn't work for you, it seems that some file like iTunes CDB files missing or corrupted on your device. Tenorshare iPhone Care Pro offers you a chance to recover it easily. Now let's see the detailed steps:
After that, iTunes won't prompt you sync session failed to start iPhone/iPad/iPod and continue to sync your contents with iPhone freely. If this method also can't solve your problem, leave a message in the comment place and we will see what we can do for you.