Black materials (even on preview)

Hey

So It appears that all the materials in this particular scene have become black and don’t appear to be receiving any light at all either. This includes the preview mesh in the material editor and even the material thumbnails as well. I don’t feel that this would be a lighting issue because it’s happening to the preview mesh as well. Any thoughts on what the problem might be?

Just as an extra to test something out. I tried in the test material there messing around with the emissive as well. when I put a single vector of 1 into it it becomes white, but any higher than 1 and it should glow but doesn’t. So I tried multiplying a 3 vector (blue colour) by 1000 and plugging that into emissive and it just stays white. Not at all sure whats going on.

I have same problem. Could you able to solve it?