Cannot turn on Media Sharing in Catalina

I have the same problem and reauthorising my Mac does not help, it just says that my Mac was already authorised and it has been reauthorised again. I have 4 Macs authorised on my account.

Update: after setting the correct folder for the media (iTunes) library I managed to switch on Home Sharing, not by selecting Media Sharing first (that still didn't work), but by selecting the Home Sharing box directly. This time it asked me for my pwd and Home Sharing was enabled.

I had the same issue, and the re-autorization in Music/TV apps and also the log-off/log-in of my iCloud account in System Preferences didn't solve. After several trials, I managed to check the Media Sharing box only after I signed in with my Apple ID on the Apple Support website via Safari browser, as this operation asked me to enter the security code (which popped up on my Mac) to give some kind of authorization (despite before upgrading to Catalina I had signed in with my Apple ID via browser more than once).

(Re)authorize your computer for your Apple ID.

tt2

Wow, this fixed it for me, thank you! You think a little error message might alleviate a lot of frustration.

You're welcome. 🙂

Better yet if the checkbox was active, but made you authorize you computer if needed when selected.

tt2