Failed to create state object

[endlessPi]

I got an error of "Failed to create state object", the return value by "d3d.device->CreateStateObject" indicates that "E_INVALIDARG One or more arguments are invalid."

But I just went through the code and it all looks fine (debug layer doesn't report any error) and I have no problem running the IntroToDXR. Could you give me a hint about what could be problem?

I have a GTX 1070 with driver version 471.11, Windows SDK version 10.0.19041.0.