attempt to index global 'char' (a nil value). How to fix this?

The scripts works in test mode, but didn't work after I start server. The script work when I reset my character. I'm trying to create pink 'fireball'

In the Player1 Roblox studio output it says this

16:51:07.751 - Players.Player1.Backpack.Massive Pinkball.LocalScript:5: attempt to index global 'char' (a nil value)
16:51:07.752 - Stack Begin
16:51:07.753 - Script 'Players.Player1.Backpack.Massive Pinkball.LocalScript', Line 5
16:51:07.754 - Stack End

This is the local script

local Tool = script.Parent
play = game.Players.LocalPlayer
mouse = play:GetMouse()
char = play.Character
hum = char.Humanoid


local en = true
Tool.Activated:connect(function()
if not en then return end
en = false
Tool.RemoteEvent:FireServer(mouse.Hit)

wait(0.5)
en = true

end)

and this is the server script.

local Tool = script.Parent
play = Tool.Parent.Parent 
mouse = play:GetMouse()
char = play.Character
hum = char.Humanoid
root = char.HumanoidRootPart

local en = true

Tool.RemoteEvent.OnServerEvent:connect(function(play,mousehit)
    local a = hum:LoadAnimation(Tool.Throw)
    a:Play()
    root.CFrame = CFrame.new(root.Position,root.Position + Vector3.new(mousehit.lookVector.x,0,mousehit.lookVector.z))
    wait(0.7)
    local pinkball = Tool.Handle:clone()
    pinkball.CFrame = Tool.Handle.CFrame
    local bv = Instance.new("BodyVelocity")
    bv.MaxForce = Vector3.new(1e8,1e8,1e8)
    bv.Velocity = mousehit.lookVector * 50
    bv.Parent = pinkball
    pinkball.CanCollide = false
    pinkball.Parent = game.Workspace
    game.Debris:AddItem(pinkball,4)
    local ten = true
    pinkball.Touched:connect(function(hit)
        if not ten then return end
        ten = false
        local ehum = hit.Parent:findFirstChild("Humanoid")or hit.Parent.Parent:findFirstChild("Humanoid")
        if ehum and ehum ~= hum then
            ehum:TakeDamage(10)
        elseif hit.Anchored == true and hit.CanCollide == true then
            for i=1,10 do
                local part = pinkball:clone()
                part.Size = Vector3.new(0.5,0.5,0.5)
                part.CFrame = pinkball.CFrame
                part.BodyVelocity.Velocity = Vector3.new(math.random(-30,30),math.random(-30,30),math.random(-30,30))
                part.Parent = game.Workspace
                game.Debris:AddItem(part,1)
            end
        end

        wait()
        ten = true
    end)

end)

Thank you