I removed that version of the material from the latest plugin. I don’t have a copy here to look at, but if there is something broken with it, its probably the same old Primitive ID stuff that needs replacing.
ie, there is a line similar to this near the top, you could try using this line (all primitive properties must be accessed this way now):
float3 localcamvec = normalize( mul(Parameters.CameraVector, GetPrimitiveData(Parameters.PrimitiveId).WorldToLocal) ) * StepSize;
A similar line needs changing in the Box Intersection function feeding the main raymarch.
That IBL material just used a cubemap for lighting. The 2nd texture was a tiling noise with directional AO and shadowing prebaked in.
I ended up not continuing that particular prototype because the new methods with SkyAtmosphere basically make it obsolete. See the volumetric cloud prototype under the Volumetrics plugin (available on github only so far) for an idea.