DESCRIPTION There is a bug also present in SDDM ( https://github.com/sddm/sddm/issues/2168 ) that cause the apprition of a black screen instead of the login screen if the monitor is off when booting (or the HDMI switch is not enabled in my case). STEPS TO REPRODUCE 1. Boot with the monitor off or disconnected 2. 3. OBSERVED RESULT See the black screen EXPECTED RESULT The apparition of the plasma login screen SOFTWARE/OS VERSIONS Operating System (available in the Info Center app, or by running `kinfo` in a terminal window): KDE Plasma Version: 6.6.90 (6.7 beta) KDE Frameworks Version: 6.27.0 Qt Version: 6.11.1 ADDITIONAL INFORMATION
I can confirm I have observed the same issue on my single HDMI monitor (Asrock Challenger CL25FF) setup whenever the monitor is turned off. SOFTWARE/OS VERSIONS: Operating System: Fedora Linux 44 KDE Plasma Version: 6.6.5 KDE Frameworks Version: 6.27.0 Qt Version: 6.11.1 Kernel Version: 7.0.12-201.fc44.x86_64 (64-bit) Graphics Platform: Wayland
As precised on the sddm issue ticket an, at least partial, fix has been added to sddm https://github.com/sddm/sddm/commit/da0b64d8e2378c4bce16cbea6cac2ffc89ad1a4a .
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-login-manager/-/merge_requests/206
Git commit 20b39c7802018d9e840c19753384cb6b743eee73 by Oliver Beard. Committed on 14/09/2026 at 15:01. Pushed by olib into branch 'master'. frontend/greeter,wallpaper: Don't quit on last window closed When all displays have been disconnected, we should not quit the greeter, but instead wait for a display. M +3 -0 src/frontend/greeter/main.cpp M +2 -0 src/frontend/wallpaper/wallpaperapp.cpp https://invent.kde.org/plasma/plasma-login-manager/-/commit/20b39c7802018d9e840c19753384cb6b743eee73
Git commit 87e49b91e7462aedc55f7c7962589142bfeb0ba1 by Oliver Beard. Committed on 14/09/2026 at 15:18. Pushed by olib into branch 'Plasma/6.7'. frontend/greeter,wallpaper: Don't quit on last window closed When all displays have been disconnected, we should not quit the greeter, but instead wait for a display. (cherry picked from commit 20b39c7802018d9e840c19753384cb6b743eee73) M +3 -0 src/frontend/greeter/main.cpp M +2 -0 src/frontend/wallpaper/wallpaperapp.cpp https://invent.kde.org/plasma/plasma-login-manager/-/commit/87e49b91e7462aedc55f7c7962589142bfeb0ba1
Git commit 9dcaab858fc71fc71afc7dd28b3e2f5a02c78017 by Oliver Beard. Committed on 14/09/2026 at 15:18. Pushed by olib into branch 'Plasma/6.8'. frontend/greeter,wallpaper: Don't quit on last window closed When all displays have been disconnected, we should not quit the greeter, but instead wait for a display. (cherry picked from commit 20b39c7802018d9e840c19753384cb6b743eee73) M +3 -0 src/frontend/greeter/main.cpp M +2 -0 src/frontend/wallpaper/wallpaperapp.cpp https://invent.kde.org/plasma/plasma-login-manager/-/commit/9dcaab858fc71fc71afc7dd28b3e2f5a02c78017