My Iphone 6s won't sync with Itunes, what do I do?

My Iphone 6s won't sync with Itunes, what do I do? - 1

Re-route ad re-encode the OC3 optical line to the MD5 spectrum for a F4FZ code, then retry.

Amm I don't know how to do any of that xD

Is iTunes up to date?