Weapon release indicator, can't fire?

[arriflex]

I have a target in view, have slaved, rotaries to m, m, and pII, pylon selected, key on....but no ok to fire indicator in the screen.....what might I be missing?

[rtimmons]

unlock red trigger lock on handle to your left

[Mt5_Roie]

yeah make sure your Master Arm is on and that the cover on the firing button is up.