It sometimes does this and displays all black, other times it does render the model but does so with a flat colour, not the texture that the material has assigned.
What I’m trying to achieve is a textured render of GH geometry using a wood (Douglas Fir to be precise) texture.
A black rendering can be a sign of an poor or out-of-date video driver. You might run the SystemInfo command and see what is reported. Feel free to post it here if needed.
Also, make sure the normals of the mesh are pointed outward (if these are closed meshes).
I had a go at updating drivers but this didn’t seem to offer any improvement. What should i be looking for in System Info? The rendered display does show sometimes, although the paneling of the texture isn’t great: