The panel (bar) is not displayed when the monitor is woken up after being turned off earlier by the system (power saving) or by the keyboard. To restore the correct display it is necessary to restart the Plasma environment (plasmashell --replace) or a full system reboot.
Physically turning off the monitor (with the monitor button) does not cause problems.
Operating System: Kubuntu 24.10
KDE Plasma Version: 6.1.5
KDE Frameworks Version: 6.6.0
Qt Version: 6.6.2
Kernel Version: 6.11.0-9-generic (64-bit)
Graphics Platform: Wayland
Processors: 12 × 11th Gen Intel® Core™ i5-11600 @ 2.80GHz
Memory: 31.2 GiB of RAM
Graphics Processor: Mesa Intel® Graphics
Manufacturer: Micro-Star International Co., Ltd.
Product Name: MS-7D18
System Version: 1.0
Let’s run a test, cause this to happen again and before you do anything else rightclick the desktop and chose “Enter Edit Mode”. See if your panel shows up. Plasma 6.0 and above has a issue with panels not always showing or only partially showing after a reboot or suspend.
I just discovered that when I turn off the screen with the keyboard button, I have a black screen with the cursor. The previously described phenomenon occurred after turning off the screen for a long time (an hour+), now a few minutes.
I checked again. Turning off the screen for a while leads to a black screen. It does not display the menu when you click the right button.
Now I will turn off for a longer period of time and see if I can carry out this experiment.
An hour has passed. Black screen. No menu when right mouse button is pressed. The login screen works normally. Previously there was wallpaper, now there is a black screen. I don’t know what has changed.
I turned off the screen with the button on the keyboard and here is the result:
plasmashell
KPackageStructure of KPluginMetaData(pluginId:"org.kde.kupapplet", fileName: "/usr/share/plasma/plasmoids/org.kde.kupapplet/metadata.json") does not match requested format "Plasma/Applet"
kf.plasma.quick: Applet preload policy set to 1
file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/main.qml:195:25: QML FolderViewDropArea (parent or ancestor of QQuickLayoutAttached): Binding loop detected for property "minimumWidth"
qt.qml.typeresolution.cycle: Cyclic dependency detected between "qrc:/qt/qml/org/kde/desktop/private/TextFieldContextMenu.qml" and "qrc:/qt/qml/org/kde/desktop/MenuItem.qml"
kf.kio.core: Malformed JSON protocol file for protocol: "trash" , number of the ExtraNames fields should match the number of ExtraTypes fields
Toolbox not loading, toolbox package is either invalid or disabled.
qt.gui.imageio: libpng warning: iCCP: known incorrect sRGB profile
kf.kio.core: Malformed JSON protocol file for protocol: "trash" , number of the ExtraNames fields should match the number of ExtraTypes fields
qt.gui.imageio: libpng warning: iCCP: known incorrect sRGB profile
file:///usr/share/plasma/plasmoids/org.kde.plasma.private.systemtray/contents/ui/main.qml:162:21: QML KSortFilterProxyModel: Binding loop detected for property "sourceModel"
file:///usr/share/plasma/plasmoids/org.kde.plasma.private.systemtray/contents/ui/main.qml:162:21: QML KSortFilterProxyModel: Binding loop detected for property "sourceModel"
qt.qml.typeresolution.cycle: Cyclic dependency detected between "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/global/Globals.qml" and "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/ThumbnailStrip.qml"
qt.qml.typeresolution.cycle: Cyclic dependency detected between "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/global/Globals.qml" and "file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/NotificationHeader.qml"
qt.dbus.integration: Could not connect "org.cups.cupsd.Notifier" to PrinterFinishingsChanged(QString, QString, QString, uint, QString, bool) :
kameleon supported false
kameleon enabled true
qml: SystemTray ItemLoader: Invalid state, cannot determine source!
file:///usr/share/plasma/plasmoids/org.kde.plasma.kicker/contents/ui/main.qml:45: TypeError: Value is null and could not be converted to an object
QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
error getting max screen brightness via dbus: QDBusError("org.freedesktop.DBus.Error.UnknownObject", "No such object path '/org/kde/Solid/PowerManagement/Actions/BrightnessControl'")
error getting max keyboard brightness via dbus QDBusError("org.freedesktop.DBus.Error.UnknownObject", "No such object path '/org/kde/Solid/PowerManagement/Actions/KeyboardBrightnessControl'")
Process "nordvpn status" already running. Pid: 1464607
kf5idletime_wayland: This plugin does not support polling idle time
QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
QFont::setPointSizeF: Point size <= 0 (0.000000), must be greater than 0
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor"
file:///usr/share/plasma/plasmoids/org.kde.plasma.keyboardindicator/contents/ui/main.qml:61:13: Unable to assign [undefined] to bool
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo"
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor"
file:///usr/share/plasma/plasmoids/org.kde.plasma.volume/contents/ui/main.qml:76: TypeError: Cannot read property 'pulseProperties' of undefined
org.kde.pulseaudio: No object for name "@DEFAULT_SINK@"
org.kde.pulseaudio: No object for name "@DEFAULT_SOURCE@"
org.kde.pulseaudio: No object for name "@DEFAULT_SINK@"
org.kde.pulseaudio: No object for name "@DEFAULT_SOURCE@"
org.kde.pulseaudio: No object for name "alsa_input.pci-0000_00_1f.3.analog-stereo"
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor"
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor"
file:///usr/share/plasma/plasmoids/org.kde.plasma.volume/contents/ui/main.qml:76: TypeError: Cannot read property 'pulseProperties' of undefined
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo"
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor"
file:///usr/share/plasma/plasmoids/org.kde.plasma.volume/contents/ui/main.qml:76: TypeError: Cannot read property 'pulseProperties' of undefined
qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
The cached device pixel ratio value was stale on window expose. Please file a QTBUG which explains how to reproduce.
kf.plasma.quick: Exposed with no visual parent. Window positioning broken.
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo"
org.kde.pulseaudio: No object for name "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor"
xdg_surface#193: error -1: invalid window geometry size (0x0)
The Wayland connection experienced a fatal error: Błąd protokołu
I wonder if this is related to my issue? Though my panel was “shrinking” instead of disappearing completely, and would go back to normal after entering the editing mode. But maybe it’s related?
Is your panel set to “fit content”? The solution was to set it to “custom size”.