... So your choices are to try a simpler desktop environment (like XFCE)
To use the stub, call /usr/lib/jriver/MC31/mc31. You can also add the stub to your PATH if you don't want to use the full path.
So for play/pause, add a custom command "/usr/lib/jriver/MC31/mc31 /MCC 10000" and assign your chosen shortcut keys.
Did you try rebooting?
Thank you all for help... I managed to make huge progress but will need bit more help.
I installed Debian 12.4 Xfce.
I created custom shortcuts for Play/Pause, Next, Previous, Mute, Volume Up, Volume Down.
Thanks to Xfce operating system is not trying to intercept when I use multimedia keys on my remote.
Play/Pause is working
Next is working
Previous is working
Mute is working
Volume Up is not working (I see JRiver reaction but it is showing only for a moment Volume 100% but nothing is changing)
Volume Down is not working (I see JRiver reaction but it is showing only for a moment Volume 100% but nothing is changing)
I tried this 2 not working commands in terminal.
10018 and 10019 from terminal are causing the same effect like using multimedia keys (Vol up and down) on my remote.
So I think something is wrong with JRiver settings this time. I set it with internal volume control. But maybe I missed something else...
So... I'm very close to solve all problems... but still need more help...