The logs indicate that the VT switch is probably still not occurring. Can you check if when you end up on a blank screen you can get back to your session by doing the VT switch with the alt+ctrl+F keys?
Also, do you go to a greeter and enter your password before returning to the user session? Exactly what hardware are you reproducing the problem on? What video cards / drivers? I'm at a sprint and trying with the laptops here and no-one seems to be able to reproduce. We are finding that switching is running slower than we'd expect but we always get back to the guest session. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/1405349 Title: switching to activated guest session causes screen blank Status in Light Display Manager: Confirmed Status in OEM Priority Project: Confirmed Status in OEM Priority Project trusty series: Confirmed Status in lightdm package in Ubuntu: Confirmed Status in lightdm source package in Trusty: New Bug description: Hi, I switch to activated guest session, but the screen remains blank. I have to wake it up with keyboard/mouse action. How to reproduce: 1. login with your account normally. 2. switch to guest session from the panel menu "Switch Account... -> Guest Session", now it's under guest session and the display is normal. 3. switch back to your user account, then switch to guest session again. 4. The screen remains blank. I can't reproduce this issue under Precise. Vivid snapshot 22-Mar-2015 can also reproduce this issue. Package: lightdm 1.10.3-0ubuntu2 unity-settings-daemon-14.04.0+14.10.20140606~0ubuntu1 --- ApportVersion: 2.14.1-0ubuntu3.2 Architecture: amd64 CurrentDesktop: Unity DistributionChannelDescriptor: # This is a distribution channel descriptor # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor canonical-oem-stella-datong140729-kylin-trusty-amd64-20150205-2 DistroRelease: Ubuntu 14.04 InstallationDate: Installed on 2015-02-09 (1 days ago) InstallationMedia: Ubuntu 14.04 "Trusty" - Build amd64 LIVE Binary 20150205-07:08 LightdmConfig: [SeatDefaults] autologin-guest=false autologin-user-timeout=0 autologin-session=lightdm-autologin Package: lightdm 1.10.3-0ubuntu2 PackageArchitecture: amd64 ProcVersionSignature: Ubuntu 3.13.0-38.65stella1-generic 3.13.11.8 Tags: trusty third-party-packages Uname: Linux 3.13.0-38-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1405349/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp