La solution donnée par codemasters
If you use nVidia graphics, uninstall the NVIDIA Geforce Experience. (For now)
· Restart your PC and try to launch the game. It should work right away. If not, try a second launch of the game right after.
If it still doesn't work:
· While in Windows, unplug the wheel.
· Uninstall the Logitech profiler.
· Re-download the Logitech profiler for the G27 and your OS from here: http://support.logitech.com/en_us/product/g27-racing-wheel#download
· Plug in the wheel when the program prompts you to.
· Open the Logitech profiler and go to global device setting, and make sure "report combined pedals" is NOT ticked.