Unknown Error when syncing (-69)

[ipadmtl]

I'm trying to sync some pdf files to my IPAD and they won't sync. I get error 69.
There are some pdf files that worked fine and others where the writing is not clear, looks like someone painted the writing.

I've upgraded to latest OS version to no avail.

Any help is greatly appreciated. I see on forums that unknown erro 69 is quite common but no resolution so far has been posted.

 

[iPadCharlie]

Try here -- iTunes displays a -69 error when syncing iPod

 

[ipadmtl]

Already tried resetting and identified the files.

The pdfs i'm trying to sync are fine. I can read them on the computer without any problem.
I see unknown error 69 for a couple of pdfs and i know they are good. For a couple other pdfs, the writing is blurred as if someone painted on them.

Instead of restoring, i upgraded to latest iOS version but i may try a restore since nothing else works.