If the GUI is frozen but the mouse moves then this means it is the gnome-shell process that has frozen or crashed. The mouse can still move because that is done by Xorg.
... Thank you for taking the time to report this bug and helping to make Ubuntu better. It sounds like some part of the system has crashed. To help us find the cause of the crash please follow these steps: 1. Look in /var/crash for crash files and if found run: ubuntu-bug YOURFILE.crash Then tell us the ID of the newly-created bug. 2. If step 1 failed then look at https://errors.ubuntu.com/user/ID where ID is the content of file /var/lib/whoopsie/whoopsie-id on the machine. Do you find any links to recent problems on that page? If so then please send the links to us. 3. If step 2 also failed then apply the workaround from bug 994921, reboot, reproduce the crash, and retry step 1. Please take care to avoid attaching .crash files to bugs as we are unable to process them as file attachments. It would also be a security risk for yourself. ** Changed in: gnome-shell (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1858332 Title: entire UI froze ctrl + alt +f2 no response Status in gnome-shell package in Ubuntu: Incomplete Bug description: Entire system froze only mouse moved left click no response right click no response keyboard not responding could not access terminal via ctrl + alt +f2 or ctrl + alt + sys rq etc. here's the video https://www.youtube.com/watch?v=byaYLD9zyMU ProblemType: Bug DistroRelease: Ubuntu 19.10 Package: gnome-shell 3.34.1+git20191024-1ubuntu1~19.10.1 ProcVersionSignature: Ubuntu 5.3.0-24.26-generic 5.3.10 Uname: Linux 5.3.0-24-generic x86_64 ApportVersion: 2.20.11-0ubuntu8.2 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Sun Jan 5 15:22:24 2020 DisplayManager: gdm3 InstallationDate: Installed on 2015-08-23 (1595 days ago) InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805) RelatedPackageVersions: mutter-common 3.34.1+git20191107-1ubuntu1~19.10.1 SourcePackage: gnome-shell UpgradeStatus: Upgraded to eoan on 2019-10-23 (74 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1858332/+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