Black screen when trying to unlock screen

Help
1

after previous update, i have problem. when i left a device untouched for a few minutes it will turn off screen to save energy, as i set here:
image

when i try to turn on screen it seems to work, but after i enter password it just shows black screen with cursor, nothing seems to work.

this logs when i entered lock screen:

Nov 21 20:31:57 archlinux kwin_x11[1376]: kwin_core: XCB error: 3 (BadWindow), sequence: 35176, resource id: 14680111, major code: 129 (SHAPE), minor code: 6 (Input)
Nov 21 20:31:59 archlinux kscreenlocker_greet[19699]: Qt: Session management error: networkIdsList argument is NULL
Nov 21 20:31:59 archlinux kscreenlocker_greet[19699]: kf.kirigami: Failed to find a Kirigami platform plugin
Nov 21 20:32:00 archlinux kscreenlocker_greet[19699]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/components/VirtualKeyboard.qml:8:1: module "QtQuick.VirtualKeyboard" is not installed
Nov 21 20:32:00 archlinux kscreenlocker_greet[19699]: libpng warning: iCCP: known incorrect sRGB profile
Nov 21 20:32:00 archlinux kscreenlocker_greet[19699]: file:///usr/share/plasma/look-and-feel/org.kde.breeze.desktop/contents/lockscreen/MediaControls.qml:82:9: QML Image: Blocked request.
Nov 21 20:32:08 archlinux dbus-daemon[674]: [system] Activating via systemd: service name='org.freedesktop.home1' unit='dbus-org.freedesktop.home1.service' requested by ':1.293' (uid=1000 pid=19699 comm="/usr/lib/kscreenlocker_greet --immediateLock --gra")
Nov 21 20:32:08 archlinux dbus-daemon[674]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.home1.service': Unit dbus-org.freedesktop.home1.service not found.

this after i entered lock screen, waited for a few minutes for screen to turn off, then turned it on, and logged in, and it showed black screen:

Nov 21 20:57:43 archlinux plasmashell[1426]: org.kde.plasma.notifications: Trying to replace notification with id 1811 which doesn't exist, creating a new one. This is an application bug!
Nov 21 20:57:43 archlinux plasmashell[1426]: Could not find the Plasmoid for Plasma::FrameSvgItem(0x55856370e420) QQmlContext(0x55855fe04290) QUrl("file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/global/Globals.qml")
Nov 21 20:57:43 archlinux plasmashell[1426]: Could not find the Plasmoid for Plasma::FrameSvgItem(0x55856370e420) QQmlContext(0x55855fe04290) QUrl("file:///usr/share/plasma/plasmoids/org.kde.plasma.notifications/contents/ui/global/Globals.qml")
2

what are your sleep/hibernate settings?

3

is that really matters?, i don’t put it into hibernation/sleep i just display to turn off but device itself not going to sleep

after some investigation i found that kscreenlock process is using 980 mb of ram, is that even normal? It seems problem is somewhere with kscreenlock i tried entering password and as always i see black screen, but then i killed kscreenlock while i’m seeing black screen, it opened another lock screen, i entered password again and i got everything restored, it seems like kscreenlock causing this black screen not plasma itself

i also found that screen energy saving is not only problem, even if i turn off this setting wait for a couple of minutes it be same black screen.

4

Does the problem go away if you install the distro package containing the QtVirtualKeyboard QML module?

Do you have multiple monitors?

5

Fixed by disabling video lockscreen, seems to be it causing black screen

6

have the issue as well - without video lockscreen
plasma 6 with x11
i noticed that after entering the password the screen does not change back to the desktop - instead a “unlock” button appeared. after licking on it the screen turns black - mousecursor still visible but nothing else.
after pressing a key on the keyboard the desktop appears again