I can confirm this on a Ubuntu 12.04 64-bit after upgrade from 11.10. When the Brightness and Lock tool is started from command line it produces the following output:
$ gnome-control-center screen
(gnome-control-center:4353): screen-cc-panel-WARNING **: Error getting brightness: GDBus.Error:org.gtk.GDBus.UnmappedGError.Quark._gsd_5fpower_5fmanager_5ferror.Code0: gsd-backlight-helper failed:
Also, the /sys/class/backlight/ directory is empty.
Is there a way to fix this?
I can confirm this on a Ubuntu 12.04 64-bit after upgrade from 11.10. When the Brightness and Lock tool is started from command line it produces the following output:
$ gnome-control- center screen
(gnome- control- center: 4353): screen- cc-panel- WARNING **: Error getting brightness: GDBus.Error: org.gtk. GDBus.UnmappedG Error.Quark. _gsd_5fpower_ 5fmanager_ 5ferror. Code0: gsd-backlight- helper failed:
Also, the /sys/class/ backlight/ directory is empty.
Is there a way to fix this?