I don`t know, if this problem really belongs to this section. If not, just move it

After a while ManiaPlanet started to open the .gbx files. But I only downloaded tracks from TMX, for Trackmania United Forever. I openned the .gbx file and ManiaPlanet tried to start. But, of course, ManiaPlanet wasn`t able to open it, so the game crashed. Now, if I right-click on the track file and click on "Open with.." and then with "TmForever" (it even doesn`t work with "Nadeo Launcher") it doesn`t work. The game just doesn`t open the file, it just closes again ._.
I hope, that you know, how to solve this problem, otherwise I have to reinstall TrackMania -.-
regards,
Chrizz.