That's another part of the infamous "keyboard bug". The game is asking for a target because instead of waiting for you to select the area of the AOE he tries to cast one of your at-wills (binded on mouse left click). When you're not in "English US Mode" if you try to cast AOEs (let's assume you have something binded to…
Well in your "Control Panel" you should have something like "Language". Here you can set your keyboard layout to another language, in our case "English US". I have Windows 8 in italian, so I don't know if this screenshot may help you:
To fix the empty quest box bug you have to: - Close the game - Change your keyboard layout to ENG-US - Open the game - Profit Obviously they ****ed up hard with some "layout recognition" or something because this bug affects only people who doesn't have the standard ENG-US layout. *slow clap*