Hello everyone.
I start to work on a map three days ago and this morning ive got a weird problem and hammer its not opening the vmf file. When I open the vmf file i get this error:

No matter what i click Yes or On it give me another error:

I click ok and then Dont Send:

Please if anyone have this problem before or know how to solve it please help me

Thanx in advance and sorry for my bad english

You have created illegal brushwork. Brush work must have 100% flat sides. All vertexes must be alligned accordingly.

Read this on Vertex manipulation.

Have you been carving brushes (using the "carve" tool)?