Bug 431161 - kwin_core: Compositing is not possible
Summary: kwin_core: Compositing is not possible
Status: RESOLVED DUPLICATE of bug 452344
Alias: None
Product: kwin
Classification: Plasma
Component: general (show other bugs)
Version: 5.20.4
Platform: Debian unstable Linux
: NOR crash
Target Milestone: ---
Assignee: KWin default assignee
Depends on:
Reported: 2021-01-04 21:12 UTC by Apurv
Modified: 2022-04-06 19:12 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:


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Description Apurv 2021-01-04 21:12:37 UTC

After an update to Plasma 5.20.4, Kwin has started to either fail to start completely, or starts with compositor disabled.

Linux/KDE Plasma: 
KDE Plasma Version: 5.20.4
KDE Frameworks Version: 5.77.0
Qt Version: 5.15.2


Terminal output after running "kwin --replace": https://pastebin.com/92FCSuV7

In order to be able to start Kwin properly with composition, I had to go into ~/.config/kwinrc and set "OpenGLIsUnsafe" to "false" under [Compositing]
Comment 1 Vlad Zahorodnii 2021-01-05 08:28:29 UTC
Comment 2 Apurv 2021-01-05 11:40:53 UTC
(In reply to Vlad Zahorodnii from comment #1)

No, it's an intel HD. Specifically as per inxi -G it's:

OpenGL: renderer: Mesa DRI Intel HD Graphics 4400 (HSW GT2) v: 4.5 Mesa 20.3.2
Comment 3 Eduardo 2021-10-04 15:28:55 UTC
I had similar issue seemingly out of nowhere. It was working fine for months, then suddenly I started getting "kwin_core: Compositing is not possible".

I'm on Arch Linux, I updated some packages like I do everyday, but not kwin package itself. I don't know if the update is the root cause.

> In order to be able to start Kwin properly with composition, I had to go
> into ~/.config/kwinrc and set "OpenGLIsUnsafe" to "false" under [Compositing]

Setting this to "false" fixed it for me. When I looked at it, it was set to "true", but I don't know how it was set when the system was working before.
Comment 4 Nate Graham 2022-04-06 19:12:29 UTC
Yeah, this means KWin thinks your openGL capabilities are too unstable to do compositing. See Bug 452344.

*** This bug has been marked as a duplicate of bug 452344 ***