I know this thread is old but I figured this might be useful for someone. I'm guessing you have your weapons system in 'training mode'? This will allow you to perform all the normal seek, aim, lock functions but not actually release your weapons when you choose to fire. This training mode switch is the large switch on the left console right beside the four mode buttons or Air/Air Air/Ground and turn to target....
Turn the switch into the 'down' or 'off' position and your weapons should now be able to fire.
