So today I clicked ‘enable HDR’ on one of my monitors and something broke. The whole system froze up and the HDR monitor went black. If I reboot it freezes right after I login.

If I unplug that monitor or start in X11 instead of Wayland then everything is fine. Plugging the HDR monitor in while I’m logged into a Wayland session also freezes everything.

How can I disable the HDR setting? The monitor doesn’t show in System Settings whilst its unplugged so I’m hoping theirs some way to fix it on the CLI. The only place I’ve found HDR referenced is .config/kwinoutputconfig.json. I set HDR to false but after reboot it’s set to true again. I also tried deleting .config/kwinrc and .local/share/kscreen but no luck.

I’m fine with just resetting all Display settings if that’s required.

----- UPDATE ------

Bug report filed here: https://bugs.kde.org/show_bug.cgi?id=485403

Fixed by

  • Ctrl + Alt + F3 to go into terminal
  • Set HighDynamicRange and WideColorGamut to false in ~/.config/kwinoutputconfig.json
  • Execute plasmashell --replace
  • Reboot, Login, Reattach HDR Monitor

Thank you everyone for your help 🎉