The How and Why You Might Want to Use Arch's Downgrade Feature
As of 20220926, MakeMKV is broken on Arch Linux due to glib and various other files being updated in Arch but not in MakeMKV. To fix this issue which shows up as a “Fatal error”, you must install downgrade from the AUR.
This is a feature found in almost every Linux package manager but the one built designed for pacman works very easily and offers you various versions of the previous builds so that you could downgrade other programs that may act funky or are not working correctly.