Every time when I want to play a scenario on the route, I always get the warning Tracks.bin is missing please help
It doesn't really mean much, sometimes can happen with a corruption in the route of some kind, but only if you've edited it. Otherwise, just press F2, which you can then use to pass the error and continue playing.
I have found the problem, but it is wired, because I donwloaded an audio pack for the ICE T and the Scenarios doesn't work, only the quick rides
You may have accidentally overwritten (or missing) something. Doing this from right click TS in Steam / Properties should help. Also, possibly, a cache clearing, but I wouldn't guess that.