Problem installation storm island

Hi, my son has à problem with THE installation of storm island. It is installed, hou can see iT in THE game, but is has a grey scale. You can not acces iT. Can anabody tell me what THE problem could be ? Thanks.

Try the information in this thread (among others): http://forums.forza.net/turn10_postst28094_FORZA-HORIZON-2-STORM-ISLAND-ISSUES.aspx