How do I make my Trail script reload each time the player dies?

This wiki should help!

http://wiki.roblox.com/index.php?title=API:Class/Humanoid/Died

just replace the print with the code that gives the player a trail!

Use this

local trail = nil
game.Players.LocalPlayer.CharacterAdded:connect(function(char)
trail = game.Lighting.Trail:Clone()
local mouse = game.Players.LocalPlayer:GetMouse()
trail.Parent = char.Head
local attachment0 = Instance.new("Attachment",char.Head)
attachment0.Name = "TrailAttachment0"
local attachment1 = Instance.new("Attachment",char.Torso)
attachment1.Name = "TrailAttachment1"
trail.Attachment0 = attachment0
trail.Attachment1 = attachment1
end)


mouse.KeyUp:connect(function(KeyUp)
if KeyUp == '0' then
  If trail then
    trail.Enabled = false
   end
end
end)

mouse.KeyDown:connect(function(KeyDown)
if KeyDown == '0' then
  if trail then
    trail.Enabled = true
   end
end
end)

There are several problems with your script. Those are:

1. KeyDown and KeyUp are both deprecated, so you have to use UserInputService instead.

2. connect is also deprecated. The new method is Connect

3. The Lighting is not a place for storage, you are supposed to use ReplicatedStorage and ServerStorage

4. And the most important: Other players will not see the trail if FilteringEnabled is on. so you would use remote events and functions.

5. But the one causing your issue is that you have to connect the function to CharacterAdded if you want it to work if they respawn.

Solution:

Put the Trail inside ServerStorage

Put a RemoteFunction called CreateTrail in the ReplicatedStorage

Put a RemoteEvent called EnableTrail in the ReplicatedStorage

LocalScript

local player = game.Players.LocalPlayer
local Replicated = game:GetService("ReplicatedStorage")
local CreateTrail = Replicated:WaitForChild("CreateTrail")
local EnableTrail = Replicated:WaitForChild("EnableTrail")
local UserInputService = game:GetService("UserInputService")
local trail

player.CharacterAdded:Connect(function(char)
    trail = CreateTrail:InvokeServer(char:WaitForChild("Head"),char:WaitForChild("Torso"))
end)

UserInputService.InputBegan:Connect(function(input,processed)
    if trail == nil then return end
    if processed then return end
    if input.KeyCode == Enum.KeyCode.Zero then
        EnableTrail:FireServer(trail,true)
    end
end)

UserInputService.InputEnded:Connect(function(input,processed)
if trail == nil then return end
    if processed then return end
    if input.KeyCode == Enum.KeyCode.Zero then
        EnableTrail:FireServer(trail,false)
    end
end)

Script in ServerScriptService

local Replicated = game:GetService("ReplicatedStorage")
local ServerStorage = game:GetService("ServerStorage")
local Trail = ServerStorage:WaitForChild("Trail")
local CreateTrail = Replicated:WaitForChild("CreateTrail")
local EnableTrail = Replicated:WaitForChild("EnableTrail")

CreateTrail.OnServerInvoke = function(player,p1,p2)
    local new = Trail:Clone()
    local a1 = Instance.new("Attachment")
    a1.Name = "Attachment1"
    a1.Parent = p1
    local a2 = Instance.new("Attachment")
    a2.Name = "Attachment2"
    a2.Parent = p2
    new.Attachment0 = a1
    new.Attachment1 = a2
    new.Enabled = false
    new.Parent = p1
    return new
end

EnableTrail.OnServerEvent:Connect(function(player,trail,enable)
    if trail:IsA("Trail") then
        trail.Enabled = enable
    end
end)