I have this error:

triangulating all windings
triangulation failed

I was creating a map. I had this error before. I read all topics about it, but this time is too much for me. I have to know what could be a reason of that error. Why?

Because I had that error four times before and I always removed all stuffs, which i add. But it never helps. I selected all map's stuffs and try move it, it helped, but now its just too much. I can't lose my time for it. I have to know, what could be a source of the problem.

Please help me.

You have a bad brush somewhere, looks for any brushes that are heavily cut or manipulated, it can also be caused by very thin brushes.

You will have to search, delete then try to compile over and over till you find it unless you get a brush reference earlier in the compile log.