Can anyone tell me what this error message in the editor means?

I get this error message when rebuilding the terrain in the editor and am wondering if anyone knows why? Could it have something to do with the models I made?

https://i.imgur.com/3Mz9a0H.jpg

Oh dude that loop is AWESOME! anyway it seems like a terrain issue? are you using custom materials?

Thanks. I'm wanting to release it. It'll be interesting to see how it goes now that there is a cabview. lol

Oh yeah, I just made a new level and it's all good now.

last edited by Tattoo