Where do I look in iTunes to find sync errors?

Solution 1:

I had the error again this morning - three items failed to sync.

I do finally have a potential culprit. The presence of App store updates seems to correlate with these errors. It fits all the criteria so far that come to mind.

• temporary and sporadic (most of the time, I'm not in the process of downloading apps while syncing and even with simultaneous downloads, my internet is such that this is generally a 1-10 second window or less per app)
• resolves itself without needing user intervention

I've poked at this several times and it doesn't seem to correlate with the sync errors in a pattern that I can detect.

The only explanation I can guess is that there is no log where these errors are collected.

Solution 2:

Leave your device plugged into the computer. There should be a little alert icon next to the device name in iTunes. Click on that to see what the actual problems were. Information from: See iTunes for more information

In my experience, updating my apps and re-syncking has cleared the warnings.