Return of Reckoning

this is actual not for me but a friend, he claims that he can not accept quests he clicks on the them a little red speech bubble pops up where your mouse cursors is but then nothing, no white page with the quest, rewards and accept button. we have tried several things like updating the game (its up to date) changing key bindings (we cant even find that in the settings). the strange thing is his brother has an identical computer yet his works fine.

Please help

Is he running any addons that could be causing this? Have you tried a fresh re-install, or copying the files from his brothers computer onto his?

There's a limit on the amount of simultaneous quests you can accept. Is his quest log full?