iTunes on external disk - broken!
I've had this set up for literally years. Alias to the iTunes library on the external drive in the location where the iTunes folder might normally be.
The most recent security update completely WRECKED my Mac - took me hours to get it restored – and now even though the setup LOOKS correct, with the right path selected in iTunes prefs, iTunes only shows music I own in the Cloud and not any of my library on hard disk.
Interestingly, Sonos still sees everything OK.
I don't know what to try other than erase prefs - which I have doen multiple times – and re-point iTunes to teh right directors (again, dozens of times.)
Any ideas?
iMac, macOS Sierra (10.12.6), Messenger