iTunes error code 4001, - icloud music library won't update on Mac
I have had this problem at the (so I'm told) senior level of iTunes support for nearly a month now, with no solution yet forthcoming. I have about 52k tracks which I own and are on an external drive attached to my iMac (frequent backups to additional drive and to Backblaze). I also have about 21k Apple Music tracks, all carefully tagged and metadata-ed just the way I like them, which, for classical music, is a chore. However, about a month ago the icloud music library simply stopped updating on my iMac - whenever I tick the "icloud music library" box in Preferences/General, I get the same old result: the activity window shows the usual steps, "Gathering information, etc" followed by "Waiting for Apple to deliver your icloud music library", but then (after at least an hour or two) I get "Genius results cannot be updated right now, an error occurred (4001)". Naturally, we (Apple support and I) have tried all the entry-level solutions over the weeks, de-authorizing and re-authorizing, signing in and out of Apple ID, turning Genius on or off (I never use it and so the default would be "off"). I even tried to download the library to a different Mac user: pretty ugly, I just got one error message after another. This error message looks very similar to the way things were a year ago, when Match was limited to 25k tracks and one's library exceeded that, but I shouldnt have that problem at my number of tracks. And another odd thing - the whole library shows up just fine, Apple Music and all (other than additions attempted since this problem), on my iPhone and iPad. So effectively, unless I use an iOS device, I can only see and play my "owned" tracks. Anyone else have a similar issue? And a solution?!