Had same issue (devices: The name org.freedesktop.DeviceKit.Power was not provided by any .service files).
Deleting /var/lib/gdm/.ICEauthority allowed me to log in but doesn't preserve display settings.
For me this issue began after installing the nvidia drivers for my new gfx board.
Had same issue (devices: The name org.freedesktop .DeviceKit. Power was not provided by any .service files). gdm/.ICEauthori ty allowed me to log in but doesn't preserve display settings.
Deleting /var/lib/
For me this issue began after installing the nvidia drivers for my new gfx board.