Sync Error (-54)

[IndieP]

Hi Everyone,
While trying to download two new apps from iTunes onto my new iPad Air 2 (iOS 9.2) I received the sync error (This iPad cannot be synced, an unknown error occurred (-54).
However, the download of the two new apps went ahead despite the sync warning. A Google search suggests files may still be movable but only in limited numbers, and that the problem is most lightly a locked file somewhere.
If this is the case, how do you detect and unlock a locked file?
Thanks

 

[scifan57]

Have you tried restarting your computer and trying the sync again?

 

[IndieP]

Yes, the first thing I did was power down my computer and the iPad, then powered up again but the problem still persists.