select volume where dragon age II is installed

hi, im trying to install the legacy dlc for dragon age ii and it keeps giving me this "select volume where /Dragon Age II.app is installed." selecting the HD where it tells me DA2 is installed doesn't work. trying to change to the directory where the dragon age 2 launcher doesn't work, even under applications in HD. in fact, under applications the launcher is greyed out as if i can't click it. i can force select it by dragging the icon a little ways, but i still get the same error. what can i do here?