STEPS TO REPRODUCE 1. Open display configuration. 2. Set resolution to 1920x1080. Apply. 3. Set resolution to 1920x1200. Apply. OBSERVED RESULT journal contains: 2月 18 23:26:01 laptop-jin-mi kded6[15501]: unknown object (4278190080), message current_mode(o) 2月 18 23:26:01 laptop-jin-mi kded6[15501]: The Wayland connection experienced a fatal error: invalid argument 2月 18 23:26:01 laptop-jin-mi python3[1829]: kf.notifications: KDE platform plugin is loaded but SNI unavailable 2月 18 23:26:01 laptop-jin-mi systemd[1182]: plasma-kded6.service: Main process exited, code=exited, status=255/EXCEPTION 2月 18 23:26:01 laptop-jin-mi systemd[1182]: plasma-kded6.service: Failed with result 'exit-code'. EXPECTED RESULT kded doesn't quit. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.6.0 KDE Frameworks Version: 6.23.0 Qt Version: 6.10.2 Kernel Version: 6.18.9-arch1-2 (64-bit) Graphics Platform: Wayland Processors: 12 × AMD Ryzen 5 5600H with Radeon Graphics Memory: 16 GiB of RAM (15.0 GiB usable) Graphics Processor: AMD Radeon Graphics
A backtrace from kded6 would be needed. You can find the crash in Crashed Processes Viewer, and for the best info, you can "Run Interactive Debugger" to use GDB. Enable debuginfod for the session to download symbols, and always type 'c' to continue without paging. When the prompt appears, type 'bt' and copy the results to a text file and add it as an attachment to the bug.
There was no crash. The process exited with a code 255 (presumably an uncaught exception?), maybe caused by: 2月 18 23:26:01 laptop-jin-mi kded6[15501]: unknown object (4278190080), message current_mode(o) 2月 18 23:26:01 laptop-jin-mi kded6[15501]: The Wayland connection experienced a fatal error: invalid argument
Could you: 1. run `WAYLAND_DEBUG=1 kded6 --replace` 2. reproduce the bug 3. attach a file with the (very long and verbose) wayland log in it 4. Paste the last 30 or so lines of the log here Thanks!
Created attachment 189918 [details] kded logs Log attached. Last lines: [2934369.108] {Default Queue} kde_output_device_v2#49.mode(new id kde_output_device_mode_v2#4278190105) [2934369.112] {Default Queue} discarded kde_output_device_mode_v2#4278190105.size(640, 480) [2934369.115] {Default Queue} discarded kde_output_device_mode_v2#4278190105.refresh(59940) [2934369.118] {Default Queue} discarded kde_output_device_mode_v2#4278190105.flags(0) [2934369.121] {Default Queue} kde_output_device_v2#49.current_mode(nil) [2934369.125] {Default Queue} kde_output_device_v2#49.uuid("16c39404-7da8-44d8-bce0-1b8235f59599") [2934369.131] {Default Queue} kde_output_device_v2#49.edid("AP///////wBJFDQSAAAAACoYAQSlIBR4Bu6Ro1RMmSYPUFQhCADhwNHA0QCpQLMAlQCBgIFA6ikAwFEgHDBAJkRARcsQAAAYAAAA9wAKAECCACggAAAAAAAAAAAA/QAyfR6g/wEKICAgICAgAAAA/ABRRU1VIE1vbml0b3IKAToCAwsARn1lYFkfYQAAABAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAALw==") [2934369.140] {Default Queue} kde_output_device_v2#49.enabled(1) [2934369.144] {Default Queue} kde_output_device_v2#49.capabilities(8640) [2934369.148] {Default Queue} kde_output_device_v2#49.overscan(0) [2934369.150] {Default Queue} kde_output_device_v2#49.vrr_policy(0) [2934369.154] {Default Queue} kde_output_device_v2#49.rgb_range(0) [2934369.157] {Default Queue} kde_output_device_v2#49.high_dynamic_range(0) [2934369.161] {Default Queue} kde_output_device_v2#49.sdr_brightness(200) [2934369.163] {Default Queue} kde_output_device_v2#49.wide_color_gamut(0) [2934369.167] {Default Queue} kde_output_device_v2#49.auto_rotate_policy(1) [2934369.169] {Default Queue} kde_output_device_v2#49.icc_profile_path("") [2934369.173] {Default Queue} kde_output_device_v2#49.brightness_metadata(0, 0, 0) [2934369.177] {Default Queue} kde_output_device_v2#49.brightness_overrides(-1, -1, -1) [2934369.182] {Default Queue} kde_output_device_v2#49.sdr_gamut_wideness(0) [2934369.184] {Default Queue} kde_output_device_v2#49.color_profile_source(0) [2934369.187] {Default Queue} kde_output_device_v2#49.brightness(10000) [2934369.192] {Default Queue} kde_output_device_v2#49.color_power_tradeoff(0) [2934369.195] {Default Queue} kde_output_device_v2#49.dimming(10000) [2934369.199] {Default Queue} kde_output_device_v2#49.replication_source("") [2934369.203] {Default Queue} kde_output_device_v2#49.ddc_ci_allowed(1) [2934369.206] {Default Queue} kde_output_device_v2#49.max_bits_per_color(0) [2934369.211] {Default Queue} kde_output_device_v2#49.automatic_max_bits_per_color_limit(0) [2934369.214] {Default Queue} kde_output_device_v2#49.max_bits_per_color_range(4294967295, 4294967295) [2934369.216] {Default Queue} kde_output_device_v2#49.edr_policy(1) [2934369.219] {Default Queue} kde_output_device_v2#49.sharpness(0) [2934369.221] {Default Queue} kde_output_device_v2#49.priority(1) [2934369.223] {Default Queue} kde_output_device_v2#49.auto_brightness(0) [2934369.225] {Default Queue} kde_output_device_v2#49.done() xsettingsd: Loaded 16 settings from /home/jin/.config/xsettingsd/xsettingsd.conf xsettingsd: Created window 0xe00001 on screen 0 with timestamp 21091 xsettingsd: Selection _XSETTINGS_S0 is owned by 0x0 xsettingsd: Took ownership of selection _XSETTINGS_S0 unknown object (4278190092), message current_mode(o) The Wayland connection experienced a fatal error: Invalid argument Note that everything except the last two lines are printed before the resolution change. The system is KDE Linux in a QEMU virtual machine. But I can also reproduce on the host. $ kinfo Operating System: KDE Linux 2026-02-19 KDE Plasma Version: 6.6.80 KDE Frameworks Version: 6.24.0 Qt Version: 6.10.2 Kernel Version: 6.18.9-zen1-2-zen (64-bit) Graphics Platform: Wayland Processors: 12 × AMD Ryzen 5 5600H with Radeon Graphics Memory: 8 GiB of RAM (7.7 GiB usable) Graphics Processor: virgl
Can confirm, and I see why: https://invent.kde.org/plasma/plasma-workspace/-/blob/90f124373c4d04c3a4aef30b94bd1c5846b48ded/devicenotifications/devicenotifications.cpp#L329
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/6384
Git commit b597d749d580d8bd943e17b23b4562f76494e532 by Xaver Hugl. Committed on 28/03/2026 at 02:19. Pushed by zamundaaa into branch 'master'. devicenotifications: keep mode objects around until KWin removes them Otherwise we crash when the current_mode event references the mode we already deleted. M +16 -1 devicenotifications/devicenotifications.cpp M +10 -0 devicenotifications/devicenotifications.h https://invent.kde.org/plasma/plasma-workspace/-/commit/b597d749d580d8bd943e17b23b4562f76494e532
Git commit 5b967ff323fc53986f7dd69f493c58d55b6b6e26 by Xaver Hugl. Committed on 28/03/2026 at 17:02. Pushed by zamundaaa into branch 'Plasma/6.6'. devicenotifications: keep mode objects around until KWin removes them Otherwise we crash when the current_mode event references the mode we already deleted. (cherry picked from commit b597d749d580d8bd943e17b23b4562f76494e532) M +16 -1 devicenotifications/devicenotifications.cpp M +10 -0 devicenotifications/devicenotifications.h https://invent.kde.org/plasma/plasma-workspace/-/commit/5b967ff323fc53986f7dd69f493c58d55b6b6e26