A workaround is to go to System Settings then to Screen Display. You'll see a screen labeled "Unknown Display".
Click on this and you'll see that the On/Off 'switch' below will now show On. Click it to Off and the effects of the "Unknown Screen" will go away. I have a notebook with an external 24" monitor and the effects for me were - 1. The Desktop pics was duplicated in the top LH corner of my ext monitor screen with it's own Launcher (I fixed the separate launcher by setting Launcher placement to only the ext monitor but couldn't get rid of the dupe desktop pic) 2. The mouse kept flickering -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1244827 Title: [13.10] Ubuntu detects a non-existing screen Status in “xorg-server” package in Ubuntu: Incomplete Bug description: An unknown screen is shown in display configuration ProblemType: Bug DistroRelease: Ubuntu 13.10 Package: gnome-control-center 1:3.6.3-0ubuntu44 ProcVersionSignature: Ubuntu 3.11.0-12.19-generic 3.11.3 Uname: Linux 3.11.0-12-generic x86_64 ApportVersion: 2.12.5-0ubuntu2.1 Architecture: amd64 Date: Fri Oct 25 20:10:35 2013 EcryptfsInUse: Yes ExecutablePath: /usr/bin/gnome-control-center InstallationDate: Installed on 2013-10-18 (7 days ago) InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424) MarkForUpload: True ProcEnviron: LANGUAGE=es_CL:es PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=es_CL.UTF-8 SHELL=/bin/bash SourcePackage: gnome-control-center UpgradeStatus: Upgraded to saucy on 2013-10-18 (7 days ago) usr_lib_gnome-control-center: activity-log-manager 0.9.7-0ubuntu4 deja-dup 27.3.1-0ubuntu1 gnome-control-center-datetime 13.10.0+13.10.20131016.2-0ubuntu1 gnome-control-center-signon 0.1.7~+13.10.20130724.1-0ubuntu1 gnome-control-center-unity 1.3+13.10.20131004-0ubuntu1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1244827/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
