Please help, everytime when i try to load the circuit in rfactor i get this message (Error loading mesh file t0_s0.GMT to memory .

[Mujooo]

 

[R Soul]

Is this all BTB tracks or just a specific one?

It may be that the track section is too long. Try splitting it up. My preferred way is to add a cross section somewhere with the 'set material' box selected.

 

[Mujooo]

I tried to export small circuit and it happend again, and how can I add cross section. I split every curve and so that I dont have long sections if you think about that.

 

[R Soul]

For a new cross section you click the surfaces button (http://simtrackipedia.wdfiles.com/local--files/btb:buttons/surfaces.gif) then control-click on the track in 3d view. But since you've mentioned you're already using short pieces of track I doubt that will help.

Are using BTB Pro and not the Evo version?
Have you ever been able to export a track to rFactor or is this your first attempt?

There's not a lot of info in your post so it's hard to know where to begin. Perhaps uploading an example of a track would allow someone to look and see if an error can be found.