gnome-window-decorator: Screen 0 on display ":0.0" already has a decoration manager; try using the --replace option to replace the current decoration manager.
compiz: SmcOpenConnection failed: Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed
compiz: Another window manager is already running on screen: 0
compiz: No managable screens found on display :0.0
Avertissement du gestionnaire de fenêtres : L'écran 0 sur le visuel « :0.0 » a déjà un gestionnaire de fenêtres