Comment 12 for bug 309482

Btw, I still need some of the info requested above, in particular lspci -vvnn.

As well, none of your files show -nv actually being used. If you are sure it is failing when using the -nv driver, please attach an Xorg.0.log from where that was used so we can see the error.

Otherwise, my guess is just that you have some chipset that -nv doesn't support (which is why I need lspci -vvnn) so Xorg is falling back to vesa, which doesn't support what kwin needs to run, which could explain its failure.

Can you reproduce this issue with Ubuntu or only on Kubuntu? If only the latter, then my guess is this may be a kwin-specific bug.