How come the fire appears in Studio, but not online in Play Mode?

--I suggest you put this entire piece of code in a Client Sided Script. Aka local then it should work fine as usual.
Tool = script.Parent
fire = script.Parent.Chamber.Fire
mousedown = false
-- Variables

function makefire()
    local area = Instance.new("Part")
    area.CanCollide = false
    area.Size = Vector3.new(10, 10, 10)
    area.CFrame = CFrame.new(script.Parent.SpawnPos.CFrame.p)
    area.Transparency = 1
    area.Parent = workspace
    local cf = script.filter:Clone()
    cf.Parent = area
    cf.Disabled = false
    local dmg = script.damage:Clone()
    dmg.Parent = area
    dmg.Disabled = false
end

mouseDown = function(mouse)
    if not mousedown then
        mousedown = true
        while mousedown do
            makefire()
            fire.Enabled = true
            wait(1)
        end
    end
    mousedown = false
end

mouseup = function(mouse)
    mousedown = false
    fire.Enabled = false
end


Tool.Equipped:connect(function(mouse)

    local Humanoid = script.Parent.Parent.Humanoid
    mouse.Icon="rbxasset://textures\\GunCursor.png"
    animation = Instance.new("Animation")
    animation.AnimationId = "http://www.roblox.com/Asset?ID=331030667"
    animTrack = Humanoid:LoadAnimation(animation)
    animTrack:Play()

    mouse.Button1Down:connect(function() mouseDown(mouse) end)
    mouse.Button1Up:connect(function() mouseup(mouse) end)

    grip = Instance.new("Weld",script.Parent.Parent.Torso)
    grip.Part0 = script.Parent.Parent.Torso
    grip.Part1 = script.Parent.Handle
    grip.C0 = CFrame.new(0,0,-2)*CFrame.Angles(math.rad(20),math.rad(20),0)
    grip.Name = "Grip"
if script.Parent.Parent:FindFirstChild("Right Arm")then
    for _,v in pairs(script.Parent.Parent["Right Arm"]:GetChildren())do
        if v:IsA("Weld") then
            game.Debris:AddItem(v,0)
        end
    end
    end
end)
Tool.Unequipped:connect(function()
--  game.Debris:AddItem(weld2,0)
    animTrack:Stop()
    game.Debris:AddItem(animation,0)
    game.Debris:AddItem(grip,0)
    fire.Enabled = false
end)

Please upvote and accept my answer if it helped it's much appreciated.