This is an error I don't really know how to fix. I have been working on a map for some time and then after all the errors this popped up. I remember having an error like this before, but could never really fix it. So, I would really appriciate some help here.
Also, I have searched this up but in they said to delete the vertex. But I can't seem to find this so called vertex #0. I can only go low enough to vertex #1 not #0.
