Ok so it's working again for me too (I guess Apple flipped a switch), however I have some new troubles. For one, since reinstalling an older version and rebuilding my library the other day it now didn't recognize a lot of my apps that were in my mobile application folder and redownloaded about 1000 apps. The apps are saved as a duplicate in the same folder so now I have doubles of a lot of apps in the Mobile Application folder. I guess I will have to go in and remove each duplicate one by one. Also for some reason it thinks these duplicate files are new downloads and when syncing my devices it's adding 100's of apps to my iPad and iPhone.
Another issue is I would like to go back to iTunes 12.6.4 (I downgraded to 12.6.3 when I started having the issues). However I see 12.6.4 is no longer available to download from Apple's site and not even in their archive section which is very odd. Any idea where I can get the Installer Package for iTunes 12.6.4 still? Searching google just came up with dead links to Apple's site. Thanks!
Try this link: https://discussions.apple.com/docs/DOC-13022
(download links point to Apple servers)
