Upgraded to Catalina before downgrading to Mojave...big troubles
Long...
I've created a mess of my 2012 Mini: I upgraded to Catalina from Yosemite or El Capitain and found my legacy Photoshop no longer worked, so decided to downgrade to Mojave, which I have on a laptop running said Photoshop. I created a Mojave install drive following found instructions and applied to Mac Mini.
Now, Mini with Mojave has seemingly partitioned itself with a Catalina drive and a Data drive running Mojave. The main Data drive no longer has my wife's user except in a "Previous Content" User's folder which I can't access.
I haven't been able to restore from Time Machine, which is on an Airport Time Capsule. I see there are 2 options- Mini.backupbundle & Mac mini.sparsebundle, which I believe 1 is newly created with Catalina or Mojave. The original back up does not seem accessible to restore. I also tried using Migration Assistant without success.
Ideally, if I can get Mini running Mojave with both users, perfect; otherwise I'll settle for Catalina or previous OS. Any help appreciated.
Mac mini, macOS 10.14