Remember: Always own a physical backup of your discs. Ripping is for fair use and convenience. Never share your dumped keys publicly besides the official KEYDB submission, as doing so violates copyright laws in many jurisdictions.
Email that dump file to the MakeMKV support address (usually found in the program log). This helps the developer add the key to the next update. Summary Checklist Check preferences. makemkv volume key is unknown
Don't waste hours banging your head against the wall. If you have updated everything, flashed your drive, and searched the forums: Remember: Always own a physical backup of your discs