This just happened. I was increasing a few render settings and poof, it went white. I closed Blender, re-opened it and this is just my life now.
ok, I’ve diagnosed it to one light. There’s this one light that if I turn it on, causes everything to go white, as thought it’s a billion watts or something, but it’s only 4000 and similar lights in the scene are the same brightness but work fine.
Ah, further diagnosed it. The point light had turned into a sun.
I always get confused for a second when everything is white and then I remembered that the values going from point to sun are crazy. Maybe a bug report is needed.