Hi Ilias, thanks for your quick response and support. As I said, I am new at this. Never worked with the WED Tool. But based on your comment I went into the WED Guide and read up on "Boundary creation". I did not think I had to create or modify the boundary, as I started with a completed airport. However, lengthening the runway must have destroyed the original boundary. So I went into my airport in the WED tool, created a boundary around the new runway and airport, and oh wonder .... the bump in the runway is gone. Fantastic. Thanks again for your help. For now I will stay away from the mesh ..... no idea how to work with it, or what I can do.