A few questions for your friend: How was he joining the campaign? Through the launch link on the campaign page, invite email, Google Hangouts, or something else? Does his account work normally? Can he join other campaigns and view the rest of the website? Have him try all the steps on this page: <a href="https://wiki.roll20.net/Solving_Technical_Issues" rel="nofollow">https://wiki.roll20.net/Solving_Technical_Issues</a>