I have found this issue to be with my user, a corrupted file on the users calendar, if you watch the Sync while it is running on his, the system will get to 87 or 217 and just hang there for a moment before giving the error from the title of this post.

I have moved half the users Calendar data to a newly created calendar folder of some other name and then re-syncd successfully. Unfortunately this user has over 200 calendar items and to move 1 by 1 until I get the corrupted entry could take days and I am not about to do that. In other cases it could be bad entries in the Tasks, Notes, Contacts or what I mentioned above the Calendar. But in every case that I have encountered this error, there is one or more items making the software crash.

Jimmie