I'm getting a strange error? Please Help

Ok so I was working on my Gun Kit and I added a grenades display. But once I went into play solo mode, I got this error:

17:42:19.406 - Players.Player1.Backpack.Gun.Gun_Main:2939: function at line 2278 has more than 60 upvalues

This is the code at line 2278:

function OnEquipped(M_Icon) --Line 2278
    wait(math.random(10, 40) / 100)
    if Humanoid.Health ~= 0 and (not Selected) then
        Selected = true

        BreakReload = false

I don't understand what's going on, What does this error mean?