I’ve had issues with my iMac restarting while not using it and this “CATERR detected! No MCA data found” has been occurring a lot lately. I am on Big Sur 11.2.1. I have a 3rd party SSD (Samsung) and I have a Sabrent Thunderbolt 3 dock, and a thunderbolt sound card (UAD).
I am keeping the sound card off for now, but it’s interesting the name Sabrent is something we have in common.