//-------------------------------------------
I just added in Shader Example:
private static BMAP bmapTest = null;

then in myMainMethod()
private static IEnumerable<ScheduleMethod> myMainMethod()
{
//Tested setup video here

//load empty level
EngFun.level_load(null);

//wait a frame
yield return 1;

//move camera back
EngVar.camera.x = -100;

//create entity
ENTITY.ent_create("model.mdl", new Vector(0, 0, 0), entityFun);

//ADDED:
bmapTest = BMAP.bmap_create( "skyDay+6.tga" );
bmapTest.bmap_to_cubemap(); //SET BREAKPOINT here to test bmapTest and it is null

yield return ScheduleMethod.wait( 1 );
}

ERROR:
A first chance exception of type 'System.NullReferenceException' occurred in ShaderExample.exe
An unhandled exception of type 'System.NullReferenceException' occurred in ShaderExample.exe

Additional information: Object reference not set to an instance of an object.
BECAUSE bmapTest is null

if i check bmapTest with
if(bmpTest != null) bmapTest.bmap_to_cubemap();

there is then no error, but bmapTest returns null
//-------------------------------------------