www.makemkv.com

I am using MakeMKV from the command line under Linux. It works great but I get this error

"ILLEGAL REQUEST:MEDIA REGION CODE IS MISMATCHED TO LOGICAL UNIT REGION'

on some discs. I read the fix for this is to disable auto and use cellwalk mode.

http://www.makemkv.com/forum2/viewtopic.php?f=7&t=5607

Is there a way to do this from command line? Or even better just revert to this mode automatically when this error occurs?

I have seen some spurious region code failure errors with version 1.8.1 under Windows. Exit MakeMKV and restart it, the same disk would read just fine.

No clue why, because the two drives in question do not have a region set yet; Neither has ever been used with anything BUT MakeMKV, and MakeMKV doesn't really need it set.

Instead of enabling cellwalk, you can just change the region of your drive. You only need to do it once though.