Vector flattens which cross a QMID 11 boundary are not split at the second crossing. The following shows a simple flatten in TmfViewer and the results in FSX:http://www.geo-davison.demon.co.uk/Shp2Vec.jpghttp://www.geo-davison.demon.co.uk/Shp2Vec2.jpgThe default flatten at Carlisle (EGNC) shows this effect. To the West of the QMID 11 boundary, the surface is flat, to the East, there is no flattening.George

This is not a Shp2Vec problem. From your image, it looks like something funny is happening on the game side.The "break points" you are referring to are merely the first point in the polygon. TmfViewer draws these in a different pen than the rest of the points. In your example the first points for two of the polygons are being covered up by points of the other two polygons.I'll ask someone to investigate what is happening in-game (using your files posted on FSDeveloper). Please do not expect a reply here.-Doug

Thanks Doug, I think you are correct. I have just set up the same flight and now I can see only half of the flatten.George

Problem solved. It was due to the the priority of the flatten with respect to the Horizon 1.4M textures.George