We are having the same issue. Response from Support:
"Please bear with me while I send your issue for investigation. You can contact us after a few weeks.
With that being said, I would just suggest you to uninstall and reinstall your iTunes on your Mac. If your using Windows, just reinstall it. Visit this site to download the new iTunes:
If you have questions regarding this matter, please let me know. I'll be more than glad to help you out.
Have a great day and Happy New Year!"
Well, our OS is just one version lower than the requirements, so we can't download it, and also are fearful we would lose our library, anyway.
Glad to hear it is not just us, and appears to be an Apple issue. Will continue to pursue a solution. Let us know if you find out anything else.