Why does it work in single player but not in server side?

For some reason the script dont below does work in single player when I test it in studio but does not work on any server.. Why?

fff = script.Parent.Parent.Inside
function Click()
wait(4)
script.Parent.Text = "Insterting Scripts"
wait (0.25)
script.Parent.Text = "Loading Interface"
wait (0.25)
script.Parent.Text = "Loading the map"
wait (0.25)
script.Parent.Text = "Loading mobs"
wait (0.25)
script.Parent.Text = "Loading the stats"
wait (0.25)
script.Parent.Text = "Purchasing some weapons"
wait (0.25)
script.Parent.Text = "Loading the NPCs"
wait (0.25)
script.Parent.Text = "Killing some monsters"
wait (0.25)
script.Parent.Text = "Loading Interface"
wait (0.25)
script.Parent.Text = "Loading the map"
wait (0.25)
script.Parent.Text = "Loading mobs"
wait (0.25)
script.Parent.Text = "Loading the stats"
wait (0.25)
script.Parent.Text = "Purchasing some weapons"
wait (0.25)
script.Parent.Text = "Clearing stuff"
wait (0.25)
script.Parent.Text = "Loading Armor"
wait (0.25)
script.Parent.Text = "Loading the objectives"
wait (0.25)
script.Parent.Text = "Rekting some bad guys"
wait (0.25)
script.Parent.Text = "Loaded!"
script.Parent.Parent.Parent.Parent.Parent.Character.Humanoid.Health = 0
end
script.Parent.Parent.Parent.BackGround.MouseEnter:connect(Click)

function Click()
    script.Parent.Parent.Parent.BackGround.Visible = false
    script.Parent.Parent.Parent.LoadingScreen:Play()
    wait(5)
    coroutine.resume(coroutine.create(function()
for i = 0,1.01,0.01 do
fff.Size = UDim2.new(i,0,1,0)
wait()
end
end))
end
script.Parent.Parent.Parent.BackGround.MouseEnter:connect(Click)