Script only works on testing mode, not in the actual game itself?

The script doesn't work in server but only in testing mode. It's a localscript placed in StarterGUI.

`local p = script.Parent.Parent
char = p.Character
repeat wait() until char
hum = char.Humanoid
local mouse = p:GetMouse()
colors = {"Really red","Dark stone grey"}
mouse.KeyDown:connect(function(key)
    if key == "v" then
        ball = Instance.new('Part', char.Torso)
        ball.Size = Vector3.new(3,3,3)
        ball.BrickColor = BrickColor.new('Really red')
        ball.Material = "Neon"
        ball.CanCollide = false
        ball.Anchored = false
        ball.Position = char.Torso.Position
        ball.CFrame = CFrame.new(ball.Position, mouse.Hit.p)
        local bv=Instance.new("BodyVelocity",ball)
bv.maxForce=Vector3.new(math.huge,math.huge,math.huge)
bv.velocity=ball.CFrame.lookVector*130  
        mesh = Instance.new('SpecialMesh', ball)
        mesh.MeshType = "Sphere"
        ball.Touched:connect(function(hit)
        if hit.Parent ~= char and hit.Parent:findFirstChild("Humanoid") then
            ball:Destroy()
    for i= 1, 5 do
    x = script.Explosion:clone()
    x.Parent = game.Workspace
    x.BrickColor = BrickColor.new(colors[math.random(1,#colors)])
    x.Mesh.Scale = x.Mesh.Scale+Vector3.new(4,4,4)
    x.Position = hit.Position
    x.CFrame = x.CFrame*CFrame.Angles(math.random(-3,3),math.random(-3,3),math.random(-3,3))
    x.Grow.Disabled = false
    hit.Parent.Humanoid.Health = hit.Parent.Humanoid.Health - 5
    game.Debris:AddItem(x,2)
    end
    wait(6)
    ball:Destroy()
        end
        end)
    end
end)`