Backtrace: https://invent.kde.org/-/snippets/2156
#0 0x00007f1dcfa21362 in KWin::Workspace::clientArea(KWin::clientAreaOption, KWin::AbstractOutput const*, KWin::VirtualDesktop const*) const (this=0x5630f2853510, opt=KWin::WorkArea, output=0x0, desktop=0x5630f2a91ec0) at /run/media/valmar/DataSSD/KDE/Sources/plasma/kwin/src/workspace.cpp:2287 #1 0x00007f1dcfa21645 in KWin::Workspace::clientArea(KWin::clientAreaOption, KWin::Toplevel const*, KWin::AbstractOutput const*) const (this=0x5630f2853510, opt=KWin::WorkArea, window=0x5630f3b3e450, output=0x0) at /run/media/valmar/DataSSD/KDE/Sources/plasma/kwin/src/workspace.cpp:2339 #2 0x00007f1dcfa215a3 in KWin::Workspace::clientArea(KWin::clientAreaOption, KWin::Toplevel const*) const (this=0x5630f2853510, opt=KWin::WorkArea, window=0x5630f3b3e450) at /run/media/valmar/DataSSD/KDE/Sources/plasma/kwin/src/workspace.cpp:2327
screenArea = effectiveOutput->geometry(); our output is null. Sounds familar
*** This bug has been marked as a duplicate of bug 452433 ***