Desktop effects are not available on this system

[joneall]

If I go into the desktop effects panel in system settings, I see this;

Desktop effects are not available on this system due to the following technical issues.

OpenGL compositing (the default) has crashed KWin in the past.

This happens since I updated from 13.04 to 14.04 amd64 yesterday. I thought it might have something to do with the NVidia (sounds like invidious, doesn't it?) driver, so I went back to Xorg, but without rebooting. Now I do not get that message, but hitting alt+shift+f12 changes nothing. No halo around the windows.

It also says I "might want to use the XRender backend instead." I have absolutly no idea what that means.

Nor do I know anything about OpenGL or KWin and have been very happy that way -- up til now.

I have seen other entries on this problem, but none in 14.04 yet, so I am opening a new topic.

[schnelle]

I would clean cache and reset kwin (desktop effects) to default settings.

1) Logout
2) Ctrl+Alt+F1 and login
3) sudo service lightdm stop
4) rm ~/.kde/share/config/kwinrc
5) cd /var/tmp
6) sudo rm -r kdecache-*
7) sudo reboot

[sithlord48]

in the same tab teunis said is an option to set the OpenGL version . i know on some drivers not all the openGl3.1 effects will load up . try using openGL 2.0 and if that fails xrender might be your only chance with stable effects.