www.makemkv.com

One more update: I hooked up a monitor as was able to register via the GUI. The beta key worked, but the "temporary workaround key" did not. Once I did, makemkvcon works as expected from the command line. Hope that helps anyone else who runs into this issue! It will be mildly annoying if I...

I played around with it a little more, and I think the issue is that the makemkv command is to launch the GUI, and because we're running headless, there's no window manager. We should use the makemkvcon command instead, which is the command line interface. Running that seems to get past the problem ...

@Elzzon,

Any luck with this? I'm running into exactly the same issue. I'm on Mint Linux 22.1, but also on a headless machine, and also getting the same error.