I've just upgraded to KDE 4.5.0 and upon login compositing is disabled. It was always enabled in 4.4 and I had no problems with it. Here's an excerpt of my .xsession-errors:

Code: Select all

kwin(1756) KWin::CompositingPrefs::detectDriverAndVersion: GL vendor is "DRI R300 Project"
kwin(1756) KWin::CompositingPrefs::detectDriverAndVersion: GL renderer is "Mesa DRI R300 (RS400 5A62) 20090101  NO-TCL DRI2"
kwin(1756) KWin::CompositingPrefs::detectDriverAndVersion: GL version is "1.5 Mesa 7.8.2"
kwin(1756) KWin::CompositingPrefs::detectDriverAndVersion: Detected driver "radeon" , version "20090101"
kwin(1756): ""fsrestore1" - conversion of "0,0,0,0" to QRect failed"
kwin(1756) KWin::EffectsHandlerImpl::loadEffect: EffectsHandler::loadEffect : Effect  "kwin4_effect_blur"  is not supported
kded(1725)/kdecore (KConfigSkeleton) KCoreConfigSkeleton::writeConfig:
QDBusConnection: name 'org.kde.kglobalaccel' had owner '' but we thought it was ':1.6'
kwin(1756): OpenGL compositing self-check failed, disabling compositing.

I thought it could be because of the blur effect, but disabling it didn't help. What did help was disabling "functionality checks", which made compositing stay enabled (but I shouldn't need to do that). What could be the problem?

There are some similar reports (see below) and it seems (in some cases) just disabling the check resolves the problem. There's also relevant bug reports https://bugs.kde.org/show_bug.cgi?id=242413 https://bugs.kde.org/show_bug.cgi?id=227435


Are you running Arch? http://www.archlinux.org/news/507/

see posts:
viewtopic.php?f=66&t=88306&p=160361&hilit=disable+compositing#p160364

viewtopic.php?f=111&t=89782&start=0&hilit=disabling+%26quot%3Bfunctionality+checks%26quot%3B