Attempt to index nil with "Touched"? - lua

Question

Here's the deal, I'm incorporating a teleportation system with a tool on Roblox Studio. However, this error has got me stumped. I will provide the code and other useful sources below and describe the issue after.
local tool = script.Parent.Parent
local debounce = false
local afterTeleport = false
local plrName = game.Players.LocalPlayer.Name
local char = workspace:FindFirstChild(plrName)
tool.Activated:connect(function(m)
if debounce == false then
local hum = game.Players.LocalPlayer.Character.Humanoid
local anim_feet = hum:LoadAnimation(script.Parent.Animation)
local current = anim_feet
local bodyVelocity = tool.Handle.LocalScript.BodyVelocity:Clone()
debounce = true
current:Play()
wait(1.1)
local gui = script.Parent.TransitionGui:Clone()
-- Properties for UI
gui.Parent = game.Players.LocalPlayer.PlayerGui
-- Transition
gui.Frame.BackgroundTransparency = 1
wait(0.02)
gui.Frame.BackgroundTransparency = 0.8
wait(0.02)
gui.Frame.BackgroundTransparency = 0.6
wait(0.02)
gui.Frame.BackgroundTransparency = 0.4
wait(0.02)
gui.Frame.BackgroundTransparency = 0.2
wait(0.02)
gui.Frame.BackgroundTransparency = 0
-- Teleport Player Into Sky Above Them
hum.Parent.HumanoidRootPart.CFrame =
CFrame.new(Vector3.new(hum.Parent.HumanoidRootPart.CFrame.X, hum.Parent.HumanoidRootPart.CFrame.Y + 700, hum.Parent.HumanoidRootPart.CFrame.Z))
bodyVelocity.Parent = hum.Parent.HumanoidRootPart
afterTeleport = true
wait(0.02)
gui.Frame.BackgroundTransparency = 0.2
wait(0.02)
gui.Frame.BackgroundTransparency = 0.4
wait(0.02)
gui.Frame.BackgroundTransparency = 0.6
wait(0.02)
gui.Frame.BackgroundTransparency = 0.8
wait(0.02)
gui.Frame.BackgroundTransparency = 1
wait(0.02)
end
end)
char.Touched:Connect(function(interact)
local hum = game.Players.LocalPlayer.Character.Humanoid
if afterTeleport == true then
if interact:IsA("Terrain") then
if hum.Parent.HumanoidRootPart:FindFirstChild("BodyVelocity") then
hum.Parent.HumanoidRootPart.BodyVelocity:Destroy()
end
elseif interact:IsA("Part") then
if hum.Parent.HumanoidRootPart:FindFirstChild("BodyVelocity") then
hum.Parent.HumanoidRootPart.BodyVelocity:Destroy()
end
elseif interact:IsA("MeshPart") then
if hum.Parent.HumanoidRootPart:FindFirstChild("BodyVelocity") then
hum.Parent.HumanoidRootPart.BodyVelocity:Destroy()
end
end
end
end)
To me, this seems correct. But the issue is whenever I play-test the code, the output displays an error that I don't understand. The output error is:
16:35:59.453 Players.BigBetterBuilder.Backpack.Sky Port.Handle.LocalScript:58: attempt to index nil with 'Touched' 
My goal for this tool is that when it is activated, it will teleport you into the sky 700 studs above the players' current position. It will add a BodyVelocity to the player's HumanoidRootPart causing the player to slow down the decent speed, and when the player touched the ground. It should remove the BodyVelocity allowing the player to roam around without having weird gravity.
But the function that's supposed to detect when a player touches the ground isn't working. And I, unfortunately, can't seem to solve the problem.

Answer 1

You've got a timing issue in your code. At the top of your script, you are trying to access the player's character model, but when this script runs, that character might not have been loaded into the workspace yet. So, when you call char.Touched:Connect(...) it throws an error because char is null.
But you've got a different problem as well. The player's character is a Model, and Model's don't have a Touched event like Parts do. So in order to use the Touched event, you either need to attach it to platforms that a character might touch, or to the Parts inside the character model.
So try moving the char.Touched connection inside a callback that fires once the player and character have properly loaded into the game, and attach the Touched connection instead to the different Parts in the character model :
local player = game.Players.LocalPlayer
player.CharacterAdded:Connect(function(character)
-- create a helper function for checking if we're touching the ground
local function checkTouchedGround(interact)
if not afterTeleport then
return
end
local shouldRemoveVelocity = false
if interact:IsA("Terrain") then
shouldRemoveVelocity = true
elseif interact:IsA("Part") then
shouldRemoveVelocity = true
elseif interact:IsA("MeshPart") then
shouldRemoveVelocity = true
end
if shouldRemoveVelocity then
local bv = character.HumanoidRootPart:FindFirstChild("BodyVelocity", 0.1)
if bv then
bv:Destroy()
end
end
end
-- listen for any time any player parts touch the ground
for _, child in ipairs(character:GetDescendants()) do
if child:isA("BasePart") then
child.Touched:Connect(checkTouchedGround)
end
end
end)