Don't minimize the browser Log in page either. It's the only way to get into Feralheart.
Gotta keep it open to be able to play.
Plus make sure you're not in incognito/private mode.
Chrome and Firefox are usually the best browser to play games on.
And like Fireboss said, restarting home usually helps. Don't forget after you click "reset home" make sure you also click on "Go home".