Some KDE desktop effects suddenly stopped working
 

Hi,

I've been running KDE 4.10.5 on Slackware64 14.0 for the last two or three months. Everything's been running perfectly. I have the standard set of KDE desktop effects enabled, and the only extravagance is wobbly windows.

Today, all of a sudden, Windows aren't wobbly anymore. There seems to be no way to re-enable the effect. KDE settings keep complaining that "7 desktop effects can't be enabled".

Here's my video card:

I'm using the latest Nvidia proprietary driver on it, and nouveau is blacklisted.

What's puzzling here: the effect has been working for the last two months and then suddenly stopped. I'm intrigued.

Any idea what's going on here?

Check the [Compositing] section in ~/.kde/share/config/kwinrc
KDE has a habit of setting this to true and doing no further checks.

I checked, it is "false". So that doesn't seem to be the problem. Also, some of the effects still work, like transparency or animated maximizing/minimizing of a window. I'm puzzled.

Some KDE desktop effects depend on having appropriate OpenGL support (Wobbly windows and Blur spring to mind).
Does 'glxinfo | grep OpenGL' show Nvidia in the vendor string?
Is 'Backend=OpenGL' shown in the Compositing section of kwinrc?

This is an old post, but has some background. http://www.linuxquestions.org/questi...ent-has-broken
and another showing my kwinrc [Compositing] section. http://www.linuxquestions.org/questi...7/#post4362492

Got it! I had 'Backend=XRender'. I set it back to OpenGL, and now all my desktop effects are fully available again.

I think I know what happened. Yesterday I updated some packages on this machine, and there were some xorg-* packages in the set of patches. I started KDE, and then mysteriously VirtualBox crashed on startup. I thought this was a video driver related thing, and some components of my proprietary NVidia driver must have been squashed by the upgrade process. Switched to init 3, reinstalled the thing, and everything went, well, almost well. I guess KDE must have detected in the process that something's missing and must have reset the 'Backend' value.

Anyway, problem solved. Thanks very much!

Same problem
 

Changing Backend=XRender to Backend=OpenGL did not solve the problem for me.

Output of glxinfo | grep OpenGL

System Info:

My configuration also has Distro=Slackware. :D

You clearly don't have the same problem as the OP. You have no functioning OpenGL support, a 3 years old Mesa version, a different very old GPU, a different distribution and a different KDE version. So maybe you should open another thread?