forza 5 gt race

I have completed all the races with gold in the GR SERIES and it is stuck on the le manns track and wont let me finish it .it just keeps saying one more race .I have done the one more race 8 times and it wont finish.

um you do know that this is the horizon race form right? go here: http://forums.forza.net/turn10_forum3_Forza-Motorsport-5.aspx
and click on racers lounge
hope that helps:)

but that is weird because the double races are only so post to do 2 but I dont have a xbox one so sorry