MUTTER_DEBUG_USE_KMS_MODIFIERS=0 fixes the issue for me too. I will give a new try without this variable after update 42.0-1ubuntu1 is released.
-- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1966808 Title: [amdgpu][radeon] gnome-shell Wayland sessions fail to start (Failed to lock front buffer on /dev/dri/card1: drmModeAddFB2WithModifiers failed: Invalid argument) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1966808/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs