What is wrong with this design...? (Attached .sment file)

    Joined
    Jan 4, 2017
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    I'm honestly dumbfounded and a little irritated now, because there 'shouldn't ' be a problem here. The original drone setup that this was made as a blueprint from worked FINE, But this... it gives an error, and half the drones disappear. Well, to be precise 1/4 the drones vanish, one from each side.
     

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