After this Time i ask myself why can’t anybody solve this problem:
Since Day One (Day One was for me 09/29) i cannot play this game. I tried the new Game Mode “Forza Driver’s Cup” and began my first Season with the Hot Hatchbacks. The first 3 Races nothing was showing me that the Game was so critical broken until i taught better. On the forth Race at Watkins Glenn my Racetrack and almost the Rest disappeared until the Game crashed after 1 or 2 Laps driving on non-visible track. I tried many many times to end the Race to continue my Series but everytime it crashed (sometimes on the last Lap, 100 meters before the Finishline -.-).
Today just minutes ago i tried it again, same Result. The Track disappears, Game crash, everything is fu…ed up. So i decided that the Series itself could be the Problem and i tried an other Series. The first 2 Races nothing was broken. It began with Brands Hatch and after this it was Spa Francorchamps. The third Race was again Watkins Glenn and i hoped it would be fine. But unfortunate no. Same Problem, same Result. Game Crash. No one can help me. I mailed at forzafb@microsoft.com, no answer until now, i reported it In-Game to Xbox with Video, also nothing to hear.
What should I do, and dont say do not play the game until its patched because it doesnt make sense to buy a game for 100 € and dont play it.
This is really strange. I have your exact problem, but I can race on Watkins Glenn just fine. The track I have the problem with is Maple Valley. I’m just not playing championship series until it’s fixed, hopefully in the near future. I’ve tried looking for Series track listings to do series that don’t have MV but haven’t found any
I re-installed the game and it was fixed. Maybe there was an issue in the pre-downloaded data of the game that was offered before 29th of September. Now everything is fine. But lost almost an month of playing 
Your save in the cloud didn’t sync with the game when you reinstalled?
Yeah the save files did sync then i re-installed the game. I only mean i lost a month of playing the game because it was not functional at all and i have to wait for emails to get some information whats going on or what i should do. And then I deleted the game because i was in contact with some guys from forza or microsoft, this e-mail forzafb@microsoft.com, and this person told me to change my game file from the external hd to the internal. The transfer didnt go well and aborted at 37% multiple times. So i decided to delete only the raw game and re-install it and the issue was gone. Everything else as save file or vip pack and car pass i let it on the same harddrive.
I dont have an answer from the email guy since he told me to change the destination of the game that the pre-offered data was corrupted or an issue then downloading the game or something completly else happened wrong.