If you are using Nvidia then this is bug 1809407. Also...
Thank you for taking the time to report this bug and helping to make Ubuntu better. Please execute the following command only once, as it will automatically gather debugging information, in a terminal: apport-collect 1833508 When reporting bugs in the future please use apport by using 'ubuntu- bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1833508 Title: the system woke up and has not proper desktop image To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1833508/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs