Iphone 5s wont sync or backup with mac after 8.1.2

Hello,

As you can read from the title, my iPhone 5s wont sync or even backup with my mac after the new update of iOS 8.1.2

Have the latest iOS and the latest iTunes. Also, my mac is running Yosemite.

Tried with different cables (all of them original) and over Wi-Fi, always stuck with the same message:

"The iPhone ... could not be synced because the sync session failed to start"

I already try turning off and on, soft reset, hard reset, closing all the apps in background...

Please help....