Hi im having some strange issues with Arnold Render in C4D R21 on PC - I've purchased some textures from Pixel Lab and also from Greay Scale Gorillas - I can see them in the Browser but I can not Render and I get a black thumbnail with a red line around in the material window - also if I try to create a new Arnold standard surface texture, I can render but I can't see the Texture in the thumbnail - I have installed correctly, we have doubled checked also with Pixel lab and GSG and non of us understand what is going on - Can you help??????
All the best Ulrik
A red border around the material preview means there's been an error.
In this case, most likely a texture error. Check the CINEMA 4D Console (Scripts > Console or Extensions > Console)