Forza Horizon 1 reached "end of life" stats on October 20th 2016. Forza Horizon 1 and its associated DLC are no longer be available for purchase.
After October 20th 2016, players who own Forza Horizon 1 will still able to download and play the game and its associated content as normal.
Unfortunately, we no longer actively support Legacy Forza titles. Limited support is still available for matchmaking and leaderboard services.