No demo tracking; "Cannot load ... NuitrackModuleGPU.dll"

I’ve just installed trial and run demo. I see it using azure properly, but no skeleton etc (as in Can I get a code demo like Nuitrack pro)

If I switch the demo to AI mode the tracking does display.

When I run nuitrack_sample from the command line I see the message “Cannot load library module: D:\Program Files\Nuitrack\nuitrack\nuitrack/middleware/NuitrackModuleGPU.dll”. This is presumably the reason behind the failure in the demo.

From Cannot load NuitrackModuleGPU.dll I see CUDA/CUDNN may be needed; though this doesn’t seem to be mentioned anywhere in install instructions. I’ve installed recent versions of these but that does not help.

Windows 10; 1080 GPU, Nvidia 555.85 drivers, Nuitrack 0.37.20, CUDA_9.0.176, CUDNN 9.1

Any idea how to get the classic tracking working?