The original host (Threshold Entertainment) took it down, so you are probably unable to play this season on the official website any more. Fortunately, there are some other game websites who picked it up. Search for "arcane miller estate" and you'll find them.
At some points during the game, the flash files try to load some MIDI files as background music. But since the game is hosted by a third-party website, these MIDI files are usually missing. So you would see some pop-up windows saying "Page Not Found". Just ignore these errors, and the game is still playable.
Save/Load features may not work either, because they require a database on the server that stores information of ongoing games, which is hard for a third-party game website.