[vtkusers] Extension GL_VERSION_1_4 could not be loaded

[Matthias Härtel]

Hey,

iam working on a parallel rendering program. Everything works fine. But 
sometimes, i get this error:

"Extension GL_VERSION_1_4 could not be loaded."

For the parallel Rendering, i create 12 threads. Each of them create a 
own renderer and renderWindow. Then, a thread catches a new frame from a 
manager-class (mutex locked) and render this frame.
But in some case, the thread gets after renderWindow creation this error 
and gets terminated.

Did anyone know this error?

Regards,
Matthias