Roblox Attempt to index nil with 'WaitForChild' - lua

Question

I'm making a script that is supposed to find the targeted player, if a value inside the player is true, then MoveTo(). It outputs an error that says
Attempt to index nil with 'WaitForChild'
This is a server script and the error is at plr:WaitForChild("Crime",1).
Here it is:
local crime= false
local plr = nil
function findNearestTorso(pos)
local list = game.Workspace:children()
local torso = nil
local dist = 10000
local temp = nil
local human = nil
local temp2 = nil
for x = 1, #list do
temp2 = list[x]
if (temp2.className == "Model") and (temp2 ~= script.Parent) then
temp = temp2:findFirstChild("HumanoidRootPart")
human = temp2:findFirstChild("Humanoid")
if (temp ~= nil) and (human ~= nil) and (human.Health > 0) then
if (temp.Position - pos).magnitude < dist then
plr = game.Players:WaitForChild(temp2.Name,1)
print("plr")
torso = temp
dist = (temp.Position - pos).magnitude
end
end
end
end
return torso
end
while true do
wait(1)
local target = findNearestTorso(script.Parent.HumanoidRootPart.Position)
if target ~= nil and plr:WaitForChild("Crime",1).Value==true then
script.Parent.Humanoid:MoveTo(target.Position, target)
end
end

Answer 1

You can not guarantee that plr is set after findNearestTorso runs.
You set plr in the body of 3 nested if statements.
if (temp2.className == "Model") and (temp2 ~= script.Parent) then
--...
if (temp ~= nil) and (human ~= nil) and (human.Health > 0) then
if (temp.Position - pos).magnitude < dist then
plr = game.Players:WaitForChild(temp2.Name,1)
--...
if any of your if statements are not true plr will be nil
To handle that we can simply change your condition, where the error happens, to check if plr is nil before the attempt to call plr:WaitForChild
if target ~= nil and plr ~= nil and plr:WaitForChild("Crime",1).Value==true then