I signed out of forza as i usually do and when i restarted the game all of my cars and all of my skill points were gone. My money and my rank were the only thing left and i have no idea what to do.
If you know anything about this plaease help thanks.
I’d e-mail Turn10, and send a message to someone on their staff. Also, try Xbox Support, they may be able to assist you.
This may cause you to lose all of your progress if there is anything wrong or corrupted with your gamesave, but you could always try to remove your save data from console only, and redownload it from the cloud.
Thanks i will try those 
My cars dissappeared too!! I can’t find the e-mail address from turn 10!! Please help
It’s frustrating I know, same thing happened to me, but I also can’t do any races, they are gone as well. I’m sure T10 are working hard at fixing the issues, and we will all know something soon. Until then maybe just cruise like I’ve been doing, I’ve got 311 out 315 roads, and can’t find the last ones, but the scenery is great
Also send HeliosT10 a PM people were doing that when they lost their saves in FM5
I think with this game you have to be careful not to quite the game during the autosave I think that maybe that this is the problem with most issues like this or else I would of thought everybody would be losing there cars ect and not just a few player ,its so easy to not notice the autosave when you quit the game.