Troubles with devisualization/window

[ddos via Digitalmars-d-learn]

Hi!

i'm trying to get devisualization/window [1] working with some 
simple opengl calls. I have created a windows with opengl context 
using

Window window = new Window(800, 600, "My window!"w, 
WindowContextType.Opengl);

If i run
writeln("type: ", context.type);
writeln("toolkit version: ", context.toolkitVersion);
writeln("shading language version: ", 
context.shadingLanguageVersion);
i get correct information
has context
type: Opengl
toolkit version: 4.5.0 NVIDIA 347.09
shading language version: 4.50 NVIDIA

First i tried to simply call glClearColor(1,0,0,1);, this crashes 
the application (Program exited with code -1073741819)

I checked the function pointer with if(cast(void*)glClearColor 
!is null){...} and well ... it's a nullpointer the first two 
frames. Then i checked for nullpointer and called 
glClearColor(...) and glClear(...) -> no crash but the window was 
just frozen.

Does anyone use Devisualization/window on Windows with success?
Fyi, if i dont do any opengl calls the window seems to work, i 
can close it normally, it's completely white.

My example sourcecode can be found here:
https://github.com/oggs91/OpenVG_D/blob/master/demo_DvisualizationWT/source/app.d


[1] https://github.com/Devisualization/window