I’ve had a VERY long session with grok to try and resolve this. Finally found that this is missing at the top of NNERuntimeORTUtils.cpp in the NNERuntimeORT module just before the dxcore_interface.h include.
#include <initguid.h> // this is missing
#include <dxcore_interface.h>
That fixed the linker error. I’m now trying to resolve the overflow errors. It’s clear at this point that the 5.6 branch is broken.