I made a script to find the closest player/dummy for a homing fireball. When I activate the fireball, the script does detect the closest player/dummy, but it is unable to return the values for the fireball script.

Here is the local script:

local player = game:GetService("Players").LocalPlayer --get the local player 
local char --get the character model
	repeat
		wait()
		char = player.Character
	until char

local humanoid = char:FindFirstChild("Humanoid") --get the humanoid
local tool = script.Parent --get the tool
local handle = tool.Handle --get the handle
local flame = handle.Fire --get the "fireball"
local size = flame.Size --get the size of the flame
local mousedown = false --debounce so holding the mouse will not spam and kill the server

local repstorage = game.ReplicatedStorage --get the replicated storage
local shootProjectile = repstorage.shootProjectile --get the remote events

local mouse = player:GetMouse() --get the mouse


function getClosestHumanoidObject() --find the closest humanoid object that is not the local player
	local parts = game.Workspace:GetDescendants()
	local partPos = {}
	
	for key, Part in pairs(parts) do --loop through the list of children of workspace to filter the list
		
		local plName = player.Name
		local plPos = char.HumanoidRootPart.Position
		
		if Part.Parent.Name ~= player.Name then
			if Part:IsA("Humanoid") then --check if the part is a basepart/model/union
				if Part.Parent:FindFirstChild("HumanoidRootPart") then
					local HumRoot = Part.Parent:FindFirstChild("HumanoidRootPart")
				
					if HumRoot then
						print("Found the root part of " .. Part.Parent.Name)
					end
				
					local dis = (plPos - Part.Parent:FindFirstChild("HumanoidRootPart").Position).magnitude
					print("Found the distance between the root part of " .. player.Name .. " and the root part of " .. Part.Parent.Name .. ". The distance is " .. dis)
				
					table.insert(partPos, key, {Part.Name, HumRoot.Position, dis})
				end	
			end
		
			if not Part:IsA("Humanoid") then

			end
		end	
	end
	
	local Hunting = partPos[1]
	
	for x = 1,#partPos,1 do
		
		if partPos[x][3] < Hunting[3] then
			Hunting = partPos[x]
		end
		
	end
	
	if Hunting then
		print("\n")
		print("Closest humanoid: " .. Hunting[1])
		print("Position of humanoid: " .. Hunting[2])
		print("Distance from player: " .. Hunting[3])
		return Hunting[1],Hunting[2]
	else
		print("Unable to return values.")
	end	
end



function loadAnim()
	
	local equipAnim = Instance.new("Animation")
	equipAnim.AnimationId = "rbxassetid://4993868195"
	local equipTrack = humanoid:LoadAnimation(equipAnim)
	
	local shootAnim = Instance.new("Animation")
	shootAnim.AnimationId = "rbxassetid://4993903090"
	shootTrack = humanoid:LoadAnimation(shootAnim)
	
	equipTrack:Play()
	size = 5
	
end


function fire()
	shootTrack:Play()
	
	local part,position = getClosestHumanoidObject()
	shootProjectile:FireServer(handle,part,position)
end

tool.Equipped:Connect(function()
	
	loadAnim()
	
	tool.Deactivated:Connect(function()
		mousedown = false
	end)
	
	tool.Activated:Connect(function()
		mousedown = true
		fire()
		repeat
			wait()
		until not mousedown
	end)
end)

Here is the server fireball script:

local repstorage = game.ReplicatedStorage
local summonProjectile = repstorage.shootProjectile


function explodetrail(part)
	local explosion = Instance.new("Explosion",workspace)
	explosion.Position = part.Position
	explosion.BlastPressure = 1
	explosion.DestroyJointRadiusPercent = 0
	explosion.BlastRadius = 10
	explosion.ExplosionType = Enum.ExplosionType.NoCraters
	explosion.Visible = true
end

summonProjectile.OnServerEvent:Connect(function(player,handle,part,position)
	print(part)
	local stoptrail = false
	
	local projectile = Instance.new("Part")
	projectile.Shape = Enum.PartType.Ball
	projectile.Name = player.name .." 's projectile"
	projectile.Anchored = false
	projectile.Transparency = 0.75
	projectile.Size = Vector3.new(0.4,0.4,0.4)
	projectile.Parent = workspace
	projectile.Material = "Neon"
	projectile.BrickColor = BrickColor.new("Neon orange")
	projectile.CFrame = CFrame.new(handle.CFrame.p, position)
	
	local attach0 = Instance.new("Attachment",projectile)
	attach0.Position = Vector3.new(0.4,0.2,0.2)
	
	local attach1 = Instance.new("Attachment",projectile)
	attach1.Position = Vector3.new(0,0.2,0.2)
	
	
	
	local startColor = Color3.new(255, 0, 0)
	local endColor = Color3.new(255, 165, 0)
  
	local sequence = ColorSequence.new(startColor, endColor)
	
  	local tracer = Instance.new("Trail",projectile)
	tracer.Attachment0 = attach0
	tracer.Attachment1 = attach1
	tracer.Color = sequence
	
	local projectilemover = Instance.new("RocketPropulsion",projectile)
	projectilemover.CartoonFactor = 0.5
	projectilemover.Target = part
	projectilemover.MaxSpeed = 1000
	projectilemover.TurnP = 500
	projectilemover.TurnD = 10
	projectilemover.ThrustP = 500
	projectilemover.ThrustD = 0
	projectilemover.TargetRadius = 5
	
	projectilemover.ReachedTarget:Connect(function()
		stoptrail = true
		local endexplosion = Instance.new("Explosion",workspace)
		endexplosion.Position = part.Position
		endexplosion.BlastPressure = 100
		endexplosion.DestroyJointRadiusPercent = 100
		endexplosion.BlastRadius = 15
		endexplosion.ExplosionType = Enum.ExplosionType.Craters
		endexplosion.Visible = true
	end)
	
	repeat
		wait(0.5)
		explodetrail(projectile)
	until stoptrail
	
	
end)

When I activate the tool, the output says: "18:20:01.210 - ServerScriptService.projectileScript:28: bad argument #2 (Vector3 expected, got nil)"

Anonymous