It’s our family computer, and it runs iTunes for our AppleTV. It has Sierra and I can’t figure out how to upgrade it any further. I understand unexpected things will happen if you can’t upgrade an older, unsupported computer running older, unsupported systems, but the sudden disappearance of my entire iTunes library is super shocking. Some, but far from all of my music is still on my drive - I subscribe to iTunes Match, which has always been set to auto-renew, but 90% of it has vanished completely.
When I restore my library from my iTunes backup, it looks fine for a minute, but then the app blinks and everything goes away. I can replicate this behavior, even after signing out of iCloud and re-authenticating my iTunes account.
I’m not looking for solutions here. I’m just basically aghast at this behavior. I’ve been using Macs since 1990, I’ve been the tech guy when I used to work at small ad agencies. I’m tired of constant change, but I’m not fundamentally stupid or uninformed. It’s just - incredibly shocking. I plan on going through the excruciating process of trying to talk to some tech people soon and I just found the whole thing crazy.