Error 4004 Silverlight

Good evening,

i have a problem when i try to watch play.mediasetpremium.it.It uses Microsoft Silverlight, i called Mediaset and they told is a Silverlight problem, i wrote them and they told is your problem. "You need to update your video driver" they said, but how can i do it on a MacBook Air (mid 2013)?
Could you please help them to solve this problem(i surfed and other people have the same problem)
Thanks
Best regards
Nicola