I have attached a tgd which always seems to render the atmosphere in red. It will render the first cloud layer fine in the quick render, but anything above it is red and the atmosphere will never draw correctly in the preview window. I think I was playing with the atmosphere height just before it occurred if that helps.
After reading several other posts, I have tried turning off GI, changing the enviro light model, turning of enviro lighting, restarting (app and pc) but to no avail. Have I missed a workaround somewhere or is this being caused by a different issue (like user error)?