There appears to be an issue in the flatpak version of MakeMKV which is causing the application to fail to read and copy disk information. There is a thread on the MakeMKV linux forum that captures this based on the “Internal error: openssl test 0050 failed” error that the application generates on open (a Google search will find it, as I assume external links are not permitted).
The current theory is that the version of openssl in the flatpak may be involved.
This is just a heads up that this particular App flatpak is broken at the moment.
-pm