Comment 33 for bug 1166765

I hit this bug when upgrading to Nvidia driver version 340.32. I noticed this error in Xorg.0.log:

[2307136.707] (EE) NVIDIA(0): Failed to initialize the GLX module; please check in your X
[2307136.707] (EE) NVIDIA(0): log file that the GLX module has been loaded in your X
[2307136.707] (EE) NVIDIA(0): server, and that the module is the NVIDIA GLX module. If
[2307136.707] (EE) NVIDIA(0): you continue to encounter problems, Please try
[2307136.707] (EE) NVIDIA(0): reinstalling the NVIDIA driver.

So, I checked to see *which* glx module *was* being loaded:

[2307131.587] (II) LoadModule: "glx"
[2307131.706] (II) Loading /usr/lib/xorg/modules/extensions/libglx.so
[2307133.490] (II) Module glx: vendor="X.Org Foundation"
[2307133.490] compiled for 1.15.1, module version = 1.0.0
[2307133.490] ABI class: X.Org Server Extension, version 8.0

That didn't look right, so I went to the directory in the message and found two modules there:

 libglx.so libglx.so.340.32

So, it appears that, when I installed the Nvidia driver, the installer did not rename the glx drivers, so I did:

cd /usr/lib/xorg/modules/extensions/
mv libglx.so libglx.so.xorg
cp libglx.so.340.32 libglx.so

after rebooting, all is well!