Most often it happens when I open Dolphin, but not each dolphin load does it.
It also happens when I open some other apps

The log always includes QXcbClipboard::setMimeData: Cannot set X11 selection owner

Please see the logs for:
a) freeze when I open Dolphin
b) when I just switch windows by clicking the task manager until it freezes

b) opening Dolphin

Code: Select all

Sep 20 10:28:33 WORKstation kwin_x11[2955]: file:///usr/share/kwin/tabbox/thumbnail_grid/contents/ui/main.qml:127: TypeError: Type error
Sep 20 10:28:33 WORKstation kwin_x11[2955]: file:///usr/share/kwin/tabbox/thumbnail_grid/contents/ui/main.qml:127: TypeError: Type error
Sep 20 10:28:34 WORKstation kwin_x11[2955]: file:///usr/share/kwin/tabbox/thumbnail_grid/contents/ui/main.qml:33: TypeError: Type error
Sep 20 10:28:34 WORKstation plasmashell[3033]: QXcbClipboard::setMimeData: Cannot set X11 selection owner
Sep 20 10:28:54 WORKstation systemd[1]: Starting Message of the Day...
Sep 20 10:28:54 WORKstation systemd[1]: motd-news.service: Succeeded.
Sep 20 10:28:54 WORKstation systemd[1]: Finished Message of the Day.
Sep 20 10:29:10 WORKstation kioslave5[31213]: kf.kio.core: timeoutSpecialCommand() did not call finished() or error()! Please fix the kio_http KIO slave
Sep 20 10:29:14 WORKstation plasmashell[3033]: kf.service.services: KApplicationTrader: mimeType "x-scheme-handler/file" not found
Sep 20 10:29:15 WORKstation kwin_x11[2955]: qt.qpa.xcb: QXcbConnection: XCB error: 3 (BadWindow), sequence: 49167, resource id: 44040568, major code: 18 (ChangeProperty), minor code: 0
Sep 20 10:29:15 WORKstation systemd[1976]: Started Dolphin - File Manager.

b) switching windows until it froze

Code: Select all

Sep 20 10:39:00 WORKstation plasmashell[3033]: QXcbClipboard::setMimeData: Cannot set X11 selection owner
Sep 20 10:39:01 WORKstation CRON[33103]: (root) CMD (  [ -x /usr/lib/php/sessionclean ] && if [ ! -d /run/systemd/system ]; then /usr/lib/php/sessionclean; fi)
Sep 20 10:39:02 WORKstation systemd[1]: Starting Clean php session files...
Sep 20 10:39:03 WORKstation systemd[1]: phpsessionclean.service: Succeeded.
Sep 20 10:39:03 WORKstation systemd[1]: Finished Clean php session files.
Sep 20 10:39:30 WORKstation konsole[4796]: QXcbClipboard: SelectionRequest too old
Sep 20 10:39:30 WORKstation konsole[4796]: message repeated 5 times: [ QXcbClipboard: SelectionRequest too old]
Sep 20 10:39:30 WORKstation plasmashell[3033]: QXcbClipboard::setMimeData: Cannot set X11 selection owner
Sep 20 10:39:30 WORKstation konsole[4796]: QXcbClipboard: SelectionRequest too old
Sep 20 10:39:30 WORKstation konsole[4796]: message repeated 11 times: [ QXcbClipboard: SelectionRequest too old]
Sep 20 10:39:30 WORKstation plasmashell[3033]: QXcbClipboard::setMimeData: Cannot set X11 selection owner
Sep 20 10:39:30 WORKstation konsole[4796]: QXcbClipboard: SelectionRequest too old
Sep 20 10:39:30 WORKstation konsole[4796]: QXcbClipboard: SelectionRequest too old
Sep 20 10:39:30 WORKstation plasmashell[3033]: QXcbClipboard::setMimeData: Cannot set X11 selection owner

What's that X11 selection owner thing?

About the system:
DISTRIB_ID=neon
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="KDE neon User - Plasma 5.25"

plasma-workspace 4:5.25.5-0xneon+20.04+focal+release+build64

thanks