Giant black spot in scene when restarting

So every time now since I upgraded to 2018.3, I get this black spot in my scene:

This black spot shadows everything I look down in and wont go away unless I go to another scene, and even then it still persist slightly. It also shows up when I play the scene, causing everything to be dark. Is there anything I can do to fix this?

the “black spot” is the actual color of your ground.
the lighter pinkish color that fades in further away is draw distance fog.
you “fix” it by changing the scale of everything in your game to reasonable values. I think the fog starts at around 1000 units from the camera.
not sure what insane values you’re using for distances, but usually you’ll want 1 distance unit to be 1 meter. if you’re making something where the world needs to be huge, then go for something smaller, like 0.1 distance unit being 1 meter.

this is not something you set anywhere, it’s just how you decide the scale to be in your mind, and then just use that scale consistently, meaning if you decide 1 unit to be 1 meter, then a human in your game should be around 1.8 units tall, or if you decide 1 unit to be 10 meters (meaning 0.1 unit is 1 meter), then a normal human in your game would be 0.18 units tall.