Anyone know how to fix it?

[supple sequoia]

Please provide more information of your problem. I’m having trouble understanding what your trying to accomplish.

[low flicker]

first of all to remove the red lines select all the faces, right click, and click remove bad faces

but I would recommend that you just undo whatever you did

and explain what you were attempting

did you just want to fill the floor?

[dapper bolt]

i wanted to have a cut in the floor that lined up with the cut in the wall so i could select a hallway i was gonna make by just double clicking

but i've made almost an entire map since then