New test. I instaled debían 8 to run cncweb,

New test.
I instaled debían 8 to run cncweb, and I can not see the drawings in the screen. Only a black square.
Webgl is active in chrome.
All is working well, except the black square.
Any idea?

This is a good WebGL stress test: https://www.shadertoy.com/view/XsBXWt
https://www.shadertoy.com/view/XsBXWt

The vídeo chip is Sis M760.
Now is working, I changued in chrome://flags, the first option. Enable hardware GPU acceleration and forget the list of software accelation.
#ignore-gpu-blacklist

I can see the drawings well now.

The console show me: http://tree.webglrenderer: ext_texture_filter_anisotropíc extensión not supported. Trece.min.js:2

Thanks for your help.

On win xp worked very well. I only changued to Linux and the Laptop is the same.