It says the quiz olypics are not currently running. It is an ongoing bug experienced by some players. All I can recommend is to make sure you have your flash plug-in active and keep trying back for the quiz.
Of the horsemen of the apocalypse who rode upon the pale horse.
war
famine
conquest or pestilence
death
At the very least this question is missing a question mark. Even better would perhaps be: "Of the four horsemen of the Apocalypse, who rode upon the pale horse?"