Whenever I click mouse anywhere on sky this comes up: attempt to index field 'Target' (a nil value)?

local Tool = script.Parent
local mouse = game.Players.LocalPlayer:GetMouse()



local ToolEnabled = true

Tool.Activated:connect( function()
	if not ToolEnabled then
		return 
	end
	
	ToolEnabled = false
	
	if mouse.Target.Position.magnitude == _G.ve1.magnitude and _G.humanoid1.Health < 101 then
		_G.humanoid1.Health = _G.humanoid1.Health + 6
	end

ve1 is a vector3

This is not the full script but the error is in the "if statement"

The reason this errors is because mouse.Target is specifically meant for targeting parts. The skybox isn't a part, and because of that, it has no position or magnitude, which causes an error. There is no target, so it is a nil value. Try adding a conditional that checks for if there's a target in the first place, and that might fix your issue.

Hope this helped.

You need to check whether your target exists!

if mouse.Target ~= nil then
    if mouse.Target.Position.magnitude == _G.ve1.magnitude and _G.humanoid1.Health < 101 then
        _G.humanoid1.Health = _G.humanoid1.Health + 6
    end
end

The following statement checks whether the mouse's target is an object. To avoid errors simply put your code in-between the statement below.

if mouse.Target ~= nil then end

Example:

local plr = game.Players.LocalPlayer
local mouse = plr:GetMouse()

mouse.Move:connect(function()
	if mouse.Target ~= nil then 
		print(mouse.Target.Name)
	end
end)