Why does stuff only working in studio not work in the in-game server?

I have a gun that shoots, sounds, moves, and functions well in studio test mode, but everything changes when I make a server or play in-game mode.I have a gun with an aim script that aims the gun, a mouse texture to the gun, and sounds to the gun, when I go in-game or on a server it all disappears like it's just a random tool. What's wrong with it?

Link: https://www.roblox.com/item.aspx?id=589543784 Script Below:

--local humanoid = hit.Parent:FindFirstChild("Humanoid")
--[[HeadDamage = 50
BodyDamage = 25
ArmDamage = 20]]
Gun = script.Parent
--Human = script.Parent.Parent.Humanoid.Health
Ammo1 = 12
TotalAmmo1 = 24

Numerator1 = 12
DaClassName = script.Parent.Parent.ClassName
BulletSpeed = 10
LimbDamage = 15
BodyDamage = 30
HeadDamage = 60

local GunOwner = script.Parent.Parent
local player = game.Players:GetPlayerFromCharacter(GunOwner)
local character = player.Character
local mouse = player:GetMouse()
local UserInputService = game:GetService("UserInputService")


enabled = true
-- SEMIAUTOMATIC
function Equip()
    -- slot
end
--function Equippered()
function Shoot()
    --if Human > 0 then

    if Ammo1 >= 1 and enabled == true then






        Ammo1 = Ammo1 - 1
        print(Gun.Parent.Name .. " has " .. Ammo1 .." ammo out of " .. TotalAmmo1 .. " in storage.")
        enabled = false

        local Bullet = Instance.new("Part", Gun)
        Bullet.Anchored = false
        game.Debris:AddItem(Bullet, 2)
        Bullet.Shape = "Ball"
        local mesh = Instance.new("SpecialMesh", Bullet)
        mesh.MeshType = "Sphere"
        mesh.Scale = Vector3.new(1, 1, 3)
        Bullet.Size = Vector3.new(0.1, 0.1, 0.1)
        Bullet.TopSurface = "Smooth"
        Bullet.BottomSurface = "Smooth"     
        Bullet.BrickColor = BrickColor.new()
        Bullet.CanCollide = false

        Bullet.CFrame = Gun.ShootThing.CFrame




        Bullet.CFrame = CFrame.new(Bullet.Position,mouse.Hit.p)


        local v = Instance.new("BodyVelocity", Bullet)
        v.velocity = Bullet.CFrame.lookVector * (BulletSpeed * 40)
        v.maxForce = Vector3.new(math.huge, math.huge, math.huge)

        --[[Gun.Fire.Transparency = 0.5
        wait(0.2)
        Gun.Fire.Transparency = 1]]

        --[[local PE = Instance.new("ParticleEmmitter", Bullet)
        PE.]]


        --[[Gun.GunPos = Vector3.new(1.5, 0, math.random(0.3, 1))
        wait(0.08)
        Gun.GunPos = Vector3.new(1.5, 0, 0)]]



    Gun.FireSound:Play()

    Bullet.Touched:connect(HitDamage)






    function HitDamage(Part)
            if Part.Parent:FindFirstChild("Humanoid") ~= nil then
                local player = game.Players.LocalPlayer

                --local player = Gun.Parent:GetPlayerFromCharacter()

                --[[local sound = Instance.new("Sound")
                sound.SoundId = "http://www.roblox.com/asset/?id=523817138"
                sound.Parent = player.PlayerGui]]

                if Part.Name == "Head" then
                    Part.Parent.Humanoid.Health = Part.Parent.Humanoid.Health - HeadDamage
                    mouse.Icon = "http://www.roblox.com/asset/?id=517291903"
                    player.PlayerGui.HitSound:Play()
                    Bullet:Destroy()
                end
                if Part.Name == "Right Leg" or "Left Leg" or "Right Arm" or "Left Arm" then
                    Part.Parent.Humanoid.Health = Part.Parent.Humanoid.Health - LimbDamage
                    mouse.Icon = "http://www.roblox.com/asset/?id=517291903"
                    player.PlayerGui.HitSound:Play()
                    Bullet:Destroy()
                end
                if Part.Name == "Torso" then
                    Part.Parent.Humanoid.Health = Part.Parent.Humanoid.Health - BodyDamage
                    mouse.Icon = "http://www.roblox.com/asset/?id=517291903"
                    player.PlayerGui.HitSound:Play()
                    Bullet:Destroy()
                end

            wait(0.3)
            mouse.Icon = "http://www.roblox.com/asset/?id=517269307"

                if Part.Parent.Humanoid.Health <= 0 then
                    print(GunOwner.Name .. " has just killed " .. Part.Parent.Name)
                end





            --else
                    --[[local GunShotDecalThing = Instance.new("Part", game.Workspace)
                    GunShotDecalThing.Size = Vector3.new(0.3, 0.1, 0.3)
                    GunShotDecalThing.CanCollide = false
                    GunShotDecalThing.Anchored = true
                    GunShotDecalThing.Position = Part.Position
                    GunShotDecalThing.Transparency = 1
                    local GunShotDecal = Instance.new("Decal", GunShotDecalThing)
                    GunShotDecal.Texture = "http://www.roblox.com/asset/?id=338514187"

                    wait(5)
                    GunShotDecalThing:Remove()]]


            end


end











    end

wait()
enabled = true


end







--end


--[[    
local humanoid = hit.Parent:FindFirstChild("Humanoid")
Bullet.Touched:connect(function(hit)

        if humanoid then 
        humanoid:takeDamage(10)
        end
end)]]


function Death()

if Gun.Parent == character then
    Gun.Parent = game.Workspace
    if Gun.Parent == game.Workspace then
    wait(20)
    Gun:Remove()
    end
end
end
character.Humanoid.Died:connect(Death)




local mouse = player:GetMouse()

    function OnKeyDown(key)
        key = key:lower()
            if key == "r" then
                print(player.Name .. " just clicked 'R' on the keyboard.")
                    if TotalAmmo1 > 0 then
                    print(Gun.Parent.Name .. "'s gun is reloading.")
                    enabled = false
                    wait(3)

                    -- 

                    --[[print(TotalAmmo1)
                    print(Numerator1)
                    print(Ammo1)]]

                    local AmmoMath = Ammo1+TotalAmmo1 > 12 and 12 or Ammo1+TotalAmmo1

                    TotalAmmo1 = TotalAmmo1 - (Numerator1 - Ammo1)
                    if TotalAmmo1 < 0 then
                        --AmmoMath = Ammo1+TotalAmmo1
                        TotalAmmo1 = 0
                    end
                    Ammo1 = AmmoMath --Numerator1
                    enabled = true
            else
                print(Gun.Parent.Name .. " has run out of Ammunition.")

                    end
                end
            end


function BeenEquipted(Mouse)

    Mouse.Icon = "http://www.roblox.com/asset/?id=517269307"
    local camera = game.Workspace.CurrentCamera

    mouse.Button2Down:connect(function(Mouse)
        if script.Parent.Parent.ClassName == "Model" then

            wait()

        UserInputService.MouseIconEnabled = false




        Gun.GripPos = Vector3.new(0.3, 0, 0)
        wait(0.001)

        Gun.GripPos = Vector3.new(0.7, 0.1, 0)
        wait(0.001)

        Gun.GripPos = Vector3.new(1.1, 0.2, 0)
        wait(0.001)

        Gun.GripPos =  Vector3.new(1.5, 0.3, 0)

        Gun.Parent.Humanoid.WalkSpeed = 10
        camera.FieldOfView = 60
        wait(0.001)
        camera.FieldOfView = 50
        end
    end)





    mouse.Button2Up:connect(function(Mouse)
        if script.Parent.Parent.ClassName == "Model" then
            wait()

        UserInputService.MouseIconEnabled = true
        Gun.GripPos = Vector3.new(1.5, 0.3, 0)
        wait(0.001)

        Gun.GripPos = Vector3.new(1.1, 0.2, 0)
        wait(0.001)

        Gun.GripPos = Vector3.new(0.7, 0.1, 0)
        wait(0.001)

        Gun.GripPos = Vector3.new(0.3, 0, 0)
        wait(0.001)
        Gun.Parent.Humanoid.WalkSpeed = 16
        camera.FieldOfView = 60
        wait(0.001)
        camera.FieldOfView = 70
        end



    end)

end

    function Weld(x,y)
    local W = Instance.new("Weld")
    W.Part0 = x
    W.Part1 = y
    local CJ = CFrame.new(x.Position)
    local C0 = x.CFrame:inverse()*CJ
    local C1 = y.CFrame:inverse()*CJ
    W.C0 = C0
    W.C1 = C1
    W.Parent = x
end

function Get(A)
    if A.className == "Part" then
        Weld(script.Parent.Handle, A)
        A.Anchored = false
    else
        local C = A:GetChildren()
        for i=1, #C do
        Get(C[i])
        end
    end
end

function Finale()
    Get(script.Parent)
end

function IsEquipped()
    player.CameraMode = "LockFirstPerson"

end
function IsUnEquipped()
    player.CameraMode = "Classic"

end






wait()
Tool=script.Parent
CP,Torso,g=nil,nil,nil
necko=CFrame.new(0, 1, 0, -1, -0, -0, 0, 0, 1, 0, 1, 0)
getPos=function(Pos,TorsoPos)
    return Vector3.new(Pos.x,TorsoPos.y,Pos.z)
end
Turn=function(mouse,Torso,Gyro)
    g.cframe=CFrame.new(Torso.Position,getPos(mouse.Hit.p,Torso.Position))
    offset=(Torso.Position.y-mouse.Hit.p.y)/130
    mag=(Torso.Position-mouse.Hit.p).magnitude/140
    offset=offset/mag
    neck=Torso.Neck
    neck.C0=necko*CFrame.fromEulerAnglesXYZ(offset,0,0)
    arm=Torso:FindFirstChild("Right Shoulder")
    if arm~=nil then
        arm.C0=CFrame.new(1, 0.5, 0, 0, 0, 1, -6.48200512e-007, 1.00000274, 0, -1.00000274, -6.48200512e-007, 0)*CFrame.fromEulerAnglesXYZ(0,0,-offset)
    end
end
Equi=function(mouse)
    wait(.2)    
    CP=Tool.Parent
    Torso=CP.Torso
    g=Instance.new("BodyGyro")
    g.P=18000
    g.D=600
    g.maxTorque=Vector3.new(80000,80000000,80000)*50000000000000000000000000
    g.cframe=Torso.CFrame
    g.Parent=Torso
   while true do
        if Tool.Parent.className~="Model" then
            break
        end
        Turn(mouse,Torso,g)
        wait()
    end
    Torso.Neck.C0=necko
    g:Remove()
end
Tool.Equipped:connect(Equi)

script.Parent.Equipped:connect(Finale)
script.Parent.Unequipped:connect(Finale)
Finale()

function Shot()
    Gun.ShootEnd.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.ShootEnd2.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.ShootEnd3.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.ShootEnd4.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.ShootEnd5.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.ShootEnd6.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.ShootEnd7.Mesh.Offset = Vector3.new(0, 0, 0.3)
    Gun.Color.Mesh.Offset = Vector3.new(0, 0.3, 0)

    wait(0.1)
    Gun.ShootEnd.Mesh.Offset = Vector3.new(0,0,0)
    Gun.ShootEnd2.Mesh.Offset = Vector3.new(0, 0, 0)
    Gun.ShootEnd3.Mesh.Offset = Vector3.new(0, 0, 0)
    Gun.ShootEnd4.Mesh.Offset = Vector3.new(0, 0, 0)
    Gun.ShootEnd5.Mesh.Offset = Vector3.new(0, 0, 0)
    Gun.ShootEnd6.Mesh.Offset = Vector3.new(0, 0, 0)
    Gun.ShootEnd7.Mesh.Offset = Vector3.new(0, 0, 0)
    Gun.Color.Mesh.Offset = Vector3.new(0, 0, 0)
end
Gun.Activated:connect(Shot)



mouse.KeyDown:connect(OnKeyDown)
Gun.Activated:connect(Shoot)
Gun.Equipped:connect(Equip)
--script.Parent.Equipped:connect(Equippered)
script.Parent.Equipped:connect(BeenEquipted)
script.Parent.Equipped:connect(IsEquipped)
script.Parent.Unequipped:connect(IsUnEquipped)