Which version is it you've got then? Some archives already containing the correct folder structure within and it may have happend that, instead of just putting the track with the actual folder into the location folder, you've created a folder that includes the sub folders again.
so its not:
"D:\Games\GTL\GameData\Locations\Nordschleife"
for instance but
"D:\Games\GTL\GameData\Locations\GTL\GameData\Locations\Nordschleife"
Or, the name of the track folder isn't correct, for whatever reason. Can't think of anything else at the moment. Would be helpful to know the version though.