"Pedro
BTW Is it happening in other leagues?
Only your league at this time. It happened to your league because the season was ending but had not completed doing so when the service had to be restarted due to a loading issue. So it was in essence only a partial execution of the script on your league instead of completing tidily. Then it ran again, and that just adds more problems (double promotions etc.).
I anticipated that the car designs would be affected, but I have to wait for our server management team to restore a backup for me first so I can extract the old designs. This should be done tomorrow, and you will have your designs back in time for the first race.
In the meantime, I have corrected all of the promotions and relegations that ran twice and put teams in the correct tiers. A new season has also been generated.