Skill only damages in Test mode?

This script makes it so that an animation plays then an expanding yellow ball is placed at the end of the user's arm when they press z. There's a script called FireDamage inside of this script, that tells the yellow ball to make the player hit sit, and take a certain amount of damage. It works, but only in test mode.

Any idea what's wrong?

Yellow Ball script:

local Player = game.Players.LocalPlayer 
local mouse = Player:GetMouse() 
local lastUse = 0;
local char = Player.Character or Player.CharacterAdded:Wait()
local hum = char:WaitForChild("Humanoid")
Player.CharacterAdded:connect(function(character)
        char = character
    hum = char:WaitForChild("Humanoid")
end)
if not hum.Parent then
    repeat wait(0.2) until hum.Parent
end


local function onKeyDown(key) 
    local Key = key:lower()
    if key == "z" and tick()-lastUse > 10 then


       
	    lastUse = tick();  
        local x = Instance.new("Part")
        x.BrickColor = BrickColor.new("Bright yellow")
        x.Material = "Neon"
        x.CanCollide = false
        x.Transparency = 0.4
        x.Size = Vector3.new(10,10,10)
        x.TopSurface = "Smooth"
        x.BottomSurface = "Smooth"
        x.Shape = "Ball"
        x.Name = Player.Name
        x.Anchored = true
        local fd = script.fireDamage:clone()
        fd.Parent = x
        local Mesh = Instance.new("SpecialMesh")
        Mesh.MeshType = "Sphere"
        Mesh.Scale = Vector3.new(1,1,1)
        Mesh.Parent = x
      --[[  local a = Instance.new("Sound")
        a.SoundId = "http://www.roblox.com/asset/?id=260430117"
        a.Parent = x
        a.Volume = 2
        a:play()]]

	       local animTrack = hum:LoadAnimation(script.Punch)
			animTrack:Play()
			wait(1)
			animTrack:Stop()


 

        



        


       

        x.CFrame = Player.Character.Torso.CFrame*CFrame.new(2, 1 , -4)
        x.Parent = workspace 

        for explode = 1,30 do
		Mesh.Scale = Mesh.Scale + Vector3.new(0.09,0.09,0.09)
		x.Transparency = x.Transparency + 0.03
		wait(0.001)
		end

        game.Debris:AddItem(x, 0.03)

        
    end
end





mouse.KeyDown:connect(onKeyDown)

Fire Damage:

function onDamage(Part)
	if Part.Parent:FindFirstChild("Humanoid") ~= nil and Part.Parent.Name ~= script.Parent.Name and Part.Parent:FindFirstChild("ForceField") == nil  then
	
	

			Part.Parent.Humanoid.Health = Part.Parent.Humanoid.Health - script.Damage.Value
			Part.Parent.Humanoid.Sit = true
			
		end
		end
		
	


script.Parent.Touched:connect(onDamage)