** Description changed: After updating from Kubuntu 24.04 to 26.04 my system no longer works correctly. I've narrowed it down to use my external screen. I'm using a Lenove laptop, for which the external screen is connected through an external USB dock. When the system starts, and external dock is connected, the system hangs hard. ctr-alt-sysrq busier does not work. I have to press power button for several seconds to switch off the system If I do not connect external dock during boot, the system starts normally. I can connect the dock after logging in to the Wayland Kubuntu session, and still use it. But once I move my mouse cursor from the internal (laptop) screen to the external screen, the system hangs hard (again magic sysrq not working) All this worked without issue on Ubuntu 24.04, although I don't know the exact driver versions anymore. Current setup: - - Lenovo laptop + - Lenovo laptop Legion 7 16IRX9 (MT_83FD_BU_idea_FM_Legion 7 16IRX9) - CPU Intel(R) Core(TM) i9-14900HX - Nvidia Geforce RTX 4060 mobile - Wayland - Kubuntu 26.04 LTS - - Nvidia driver 595.71.05 + - Nvidia driver 595.71.05 Based on some googling I tried nvidia driver 580, adding nvidia- drm.modeset=0/1 as boot parameter, and I tried X11 session. Only the X11 session worked properly, but there I cannot scale the monitors properly (one has a 3200 pixel width, while the other has 1920) ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: plasma-session-wayland 4:6.6.4-0ubuntu2 ProcVersionSignature: Ubuntu 7.0.0-22.22-generic 7.0.0 Uname: Linux 7.0.0-22-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia zfs ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Sat May 30 20:32:36 2026 InstallationDate: Installed on 2024-11-16 (560 days ago) InstallationMedia: Ubuntu 24.10 "Oracular Oriole" - Release amd64 (20241009.4) SourcePackage: plasma-workspace UpgradeStatus: Upgraded to resolute on 2026-05-28 (2 days ago) modified.conffile..etc.logrotate.d.apport: [modified] mtime.conffile..etc.logrotate.d.apport: 2024-12-12T16:20:53.613902
** Description changed: After updating from Kubuntu 24.04 to 26.04 my system no longer works correctly. I've narrowed it down to use my external screen. I'm using a Lenove laptop, for which the external screen is connected through an external USB dock. When the system starts, and external dock is connected, the system hangs hard. ctr-alt-sysrq busier does not work. I have to press power button for several seconds to switch off the system If I do not connect external dock during boot, the system starts normally. I can connect the dock after logging in to the Wayland Kubuntu session, and still use it. But once I move my mouse cursor from the internal (laptop) screen to the external screen, the system hangs hard (again magic sysrq not working) All this worked without issue on Ubuntu 24.04, although I don't know the exact driver versions anymore. Current setup: - Lenovo laptop Legion 7 16IRX9 (MT_83FD_BU_idea_FM_Legion 7 16IRX9) - CPU Intel(R) Core(TM) i9-14900HX - Nvidia Geforce RTX 4060 mobile - Wayland - Kubuntu 26.04 LTS - Nvidia driver 595.71.05 + - USB Docking station: Club3D CSV-1585 + - External monitor HP e243i Based on some googling I tried nvidia driver 580, adding nvidia- drm.modeset=0/1 as boot parameter, and I tried X11 session. Only the X11 session worked properly, but there I cannot scale the monitors properly (one has a 3200 pixel width, while the other has 1920) ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: plasma-session-wayland 4:6.6.4-0ubuntu2 ProcVersionSignature: Ubuntu 7.0.0-22.22-generic 7.0.0 Uname: Linux 7.0.0-22-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia zfs ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: KDE Date: Sat May 30 20:32:36 2026 InstallationDate: Installed on 2024-11-16 (560 days ago) InstallationMedia: Ubuntu 24.10 "Oracular Oriole" - Release amd64 (20241009.4) SourcePackage: plasma-workspace UpgradeStatus: Upgraded to resolute on 2026-05-28 (2 days ago) modified.conffile..etc.logrotate.d.apport: [modified] mtime.conffile..etc.logrotate.d.apport: 2024-12-12T16:20:53.613902 ** Tags added: kubuntu -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2154647 Title: External screen makes system crash To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/2154647/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
