Ipod "Backing up" problem. (Sync error)

Everytime i plug in my ipod touch, (version 6) and it begins to sync , a message pops up saying "itunes has stopped working. A problem caused the program to stop working correctly. Windows will close the program and notify you if a soution is avaible" but ONLY on Step: 2 of the sync process.(which is the backing up problem)