What is this terrain glitch?

[Dingus]

I’m afraid I can’t ask this question in immense detail, but I have to know what’s going on with my terrain?
Unity worked fine for me for a long time, and now it always looks like this when I start up. Is there a way I can fix it?

[tapanui]

have you tried re-downloading unity or contacting an admin

[Owen-Reynolds]

It looks like depth fighting. Do you have two copies of the terrain?

[Dingus]

There is only one copy of the terrain, and yes, I have re-downloaded it more than once so far. I don’t like to ask questions, I love messing around and trying to figure things out for myself, but this has been going on for too long, and nothing I do seems to help it.