Have a friend who lives about 1700 miles from me asking for help with this issue.
All he wants to do is drag and drop all of his music from his computer to his phone but it doesn't seem to be working. When he goes out on the road the songs are never there. I tried talking him through this while he was away from his computer, so I only had his phone to work with.
This is as much as I could ascertain:
-He never signed up for Apple Music free trial - I think that's evident from the screen shot.
-He has no idea what iTunes Match was so I can assume he didn't have that enabled ever.
-I don't know if he had iCloud Music Library on at some point. Still confused by that.
-He's noticed that a bunch of his music is not even on his phone even though he went through the process of putting it there.
-When he looks at an iTunes purchased song, he hits the ... and selects "make available offline" and that's when he gets the warning dialog above.
Anyone come across this? I suggested hiding Apple Music on his phone as well as in iTunes. I don't know where else to go with this and I'm having a hell of a time researching this due to Apple's ridiculously generic app naming conventions.