-1 Region when Connecting Apple External Superdrive in order to play DVDs

There is no such region as -1 it is 1 did you try a DVD.......Are you trying one from a different region than 1..........Your DVD drive is automatically set to a region code the first time you play a coded DVD. If the region code for a DVD doesn’t match the current region code of your DVD drive, a dialog asks you if you want to change the code for the drive.

Change your DVD drive region in DVD Player on Mac - Apple Support

I have the exact same problem. I ended up calling Apple Support, and they told me that there is a known issue with Catalina which won't allow you to set the region. They had me try booting in safe mode and try it again, but when I inserted the DVD in the SuperDrive, it wasn't recognized.

The support person said the solution is to set the region on a Mac that has an OS version older than Catalina, then the SuperDrive will be usable by Catalina.

I haven't tried this yet - I'm trying to see if anyone I know has an older version of the software - I'm trying to avoid downgrading one of my systems, but that might be my next move.

Good Luck.

Is Apple just ignoring this problem? They've updated Catalina twice and haven't addressed it. Unfortunately, I recently updated my second laptop to Catalina too so these fixes won't work for me.

Seems negligent for Apple to ignore a bug that leaves one or their products unusable.

That's good info to know PerfectTommy, Catalina is starting to imitate Windows Vista, LOL

I had this same problem. Setting the DVD region in another computer running an older OS worked seemed to solve it.

I was able to set the region to 1 in Windows 10 Device Manager.

I did try what you said. I plugged my external DVD player into an old Mac, set the region and then plugged back into my new one that runs catalina. IT WORKS!