#997022 kwin-x11: Black screen after attempting to enable compositing

Package:
kwin-x11
Source:
kwin
Description:
KDE window manager, X11 version
Submitter:
Ben Morris
Date:
2021-10-22 14:03:03 UTC
Severity:
important
#997022#5
Date:
2021-10-22 13:53:25 UTC
From:
To:
When starting compositing in kwin (either by starting kwin with compositing
enabled, or by pressing Ctrl-Alt-F12 while kwin is running), the whole screen
goes black apart from the mouse cursor.

When this happens, kwin prints `kwin_core: Failed to initialize compositing,
compositing disable`. Further attempts to enable compositing via the keyboard
shortcut produce two lines: `kwin_core: Failed to initialize compositing,
compositing disable` and `kwin_core: XCB error: 10 (BadAccess), sequence: 2497,
resource id: 1730, major code: 142 (Composite), minor code: 2
(RedirectSubwindows)`.


Attempting to disable or enable compositing has no visible effect. The screen
simply remains black until kwin is killed.