You missed the fix to the skill try from a few weeks ago. For a while there, we could access ALL of our Bridge Officer powers, without regard to which ones were assigned or what rank slots our ship had. Big bug.
A side effect of the fix required that all users, upon first login after the patch, would have to unassign and then reassign all of the bridge officers on the "stations" tab of your character menu (accessed by hitting the "u" button).
Once you reassign your BOFFs, you should have your powers tray working again.