After 5-10 tries finally the texture occurred in the game. It's a bit buggy, in the grass is shining some asphalt but for first try not so bad. Thank you for the help! 🙂
Added 15 minutes later:
Sh*t happened.. The textures don't load anymore... The asphalt is only grey, pure grey, but it should be dark grey with 2 yellow stripes in the middle..