I'm having similar issues as above and as I've had in the past. MakeMKV was working well for a long time, but didn't like one of the latests discs that I put in, so I restarted and when I opened the GUI again, I get an error stating I'm not using the latest version and need to enter a registration key if I want to continue (I have a paid registration key that I've typed in more times than I care to do).
I've modified the settings.config file a number of times, but my edits don't effect the program. Modifying settings or entering the key within the GUI edit the config file, but I can't get it to work the other way which is very strange.
I just opened my settings.config file and my registration code is still present, so I'm not sure why it isn't working.
Here's the path to my file: /mnt/cache/Docker/apps/MakeMKV/config
And here's my settings.config file contents:
#
# MakeMKV settings file, written by MakeMKV v1.9.10 linux(x64-release)
#
app_DestinationDir = "/unRaid/Movies/Adult"
app_DestinationType = "3"
app_Key = "M-Bjb9mgHIiL......x5ygIn"
app_dtshddec = ""
I've had a similar issue in the past, but found that if I never restart the GUI, the key doesn't disappear.