In the material room simple tab if I click on "Create Simple Material" I get some boxes where I can enter details of the material. But if I click om "Create Advanced Material" all I get is the same boxes as before but they are all greyed out and nothing is clickable. I can't find any way to do anything in this mode. Is there something I have to to to activate this funcion?

I'm using Poser 14 in trial mode on Windows 11.

The 'Create Advanced Materials' button creates a PhysicalSurface in the Material Room for PBR textures.  Once you click on that button, you need to enter the Edit mode, or Material Room proper, to construct your shader.  You need to have some knowledge to assemble nodes and connect them properly for Superfly rendering.

Thank you, that makes it clear. If I create a simple material and click the advanced material button, then go to the edit tab there is a PhysicalSurface with the image maps I selected connected to the inputs.