Réponse d'un développeur sur le forum de steam :
" Ubisoft [développeur] Il y a 6 minutes
If possible, please try verifying the game files to see if there are any damaged or missing files. If you have not, please try checking for any driver updates. However, if you continue to have this problem, please submit your dxdiag and msinfo to Support here: https://support.ubi.com "
http://steamcommunity.com/app/241560/discussions/0/34095684690909808/?tscn=1408986427