thanks for the help. i am in contact with nvidia about this. the shader compiles and links without any errors or warnings.

I discovered that the functions crash when the program is not bound to the current state. according to the spec this should not be necessary for the reflection API. But I am still not able to use the GetActiveSubroutineName and -Index functions. I am currently not at my workstation. I will post a complete simple shader that shows these errors everytime