iphone could not be synced because the sync session failed to start

The current version of iTunes at the time of posting is 12.6.2.20. If you really are running Windows 7 and Apple Software Update isn't fetching the new build for some reason then download a fresh copy from iTunes - Download iTunes Now - Apple, and ignore the paragraphs below. If you have any problems with the update see Troubleshooting issues with iTunes for Windows updates.

If you run Windows XP SP 3 or Vista then iTunes is maxed out at version 12.1.3.6. (which is why I question which version of Windows you have). While it seems users with iOS 10.0 through 10.1 were able to sync and backup with this older version of iTunes, upgrading or restoring a device running iOS 10 requires iTunes 12.5.1 or later. It would also seem that iOS 10.2 broke the ability to sync with iTunes 12.1.3.6 and the minimum version for iOS 10.2 is iTunes 12.5.4.42. You can backup to iCloud.

Upgrading to Windows 7 or later would let you install the current version of iTunes, or see Move your iTunes library to a new computer if you decide it it is time for new hardware. Alternatively you could take out a subscription to iTunes Match which would allow music added to your iCloud Music Library on your computer to become available to stream or download to your device. See Subscribe to iTunes Match - Apple Support for details.

See also Import photos and videos from your iPhone, iPad, or iPod touch - Apple Support. If you unlock your device before connecting to your computer it may still register as a digital camera type device, allowing you to copy off any photos. Otherwise iCloud and Photo Stream may work, or you can use email, Dropbox, or similar tools.

tt2

i tried this and everything i could find in other support communities, but nothing seemed to work. checked some settings and realized that my default location to store music had been chnaged (maybe during an upgrade?). so my music was being stored in two different folders. changed my default back to the one location i wanted and moved everything that was in the other folder back to this location, helped itunes find the songs, sync'd...everything works fine now. it worked for me.

iphone 4 with latest software

latest version of itunes

windows xp

i'm also facing the same problem but i'm using windosw7 ultimate 32bit and itune version is 12.1.3.6, what i shoud do?

(iphone could not be synced because the sync session failed to start)