Sorry, I have a little question for you. I am italian and I signed up to this site from some weeks. It' s difficult for me to explain my problem (sorry for my english). I have to export a track from BTB to Rfactor. I have already finished to build the track (within buildings or other external objects but this is not important).I have added the terrain on both two sides of the track and I have already defined the path (fastline) of the car (with the control points) as well as i did in the other tracks (that i have succesfully exported). Now, when i click the export button, the BTB shows this message: "Can't export: la lunghezza non può essere minore di zero. nome parametro: lenght" I translate for you: "Can't export: length parameter can't be < 0. parameter name: lenght". I don't understand. What is the problem? 3 important things: 1-The Main window of BTB shows that track's lenght is 1.577m (so I think it is impossible that lenght parameter is < 0). - During the building of the track I loaded a background image from Google Earth (but after I remove it)- - I have resized the track when I finished building the track. I don't have the solution for this problem. Can anyone help me?