Item not added to iCloud Music Library because an error occurred
A little background, this iTunes library has travelled from computer to computer to an external drive now on my new iMac.
That said...
I just signed up for Apple Music a few weeks ago, decided to try to use it. I have my iTunes library MOSTLY in the cloud, but there's quite a bit that didn't get uploaded due to the error in the subject line. Some of them are CDs that I've loaded into iTunes. At least one of them I've verified is available in iTunes Store. Some of them are CDs I've bought from iTunes. I verified I can play them on this computer - at least when I do that, the exclamation point in a circle on the far left goes away. I just can't add them to the cloud and if I try to add one to a playlist, it tells me it's going to make that playlist unavailable in the cloud.
I'm obviously authorized to play the music on this computer.
Could these be DRM protected and that's what's causing this? The "get info" screen doesn't show DRM status if that's the cause.
Any ideas? Thanks in advance.
iMac with Retina 5K display, macOS High Sierra (10.13.3)