What does it mean when i attempt to call a _G. function with a "nil" value? (WARNING: LOTS OF CODE)

i have 3 scripts all stringed together, but for some reason, it wont let me call my _G. functions. It calls them a "nil" value. "Players.SweetAsCreampie.PlayerGui.Buttony:36: attempt to call field 'CancelTransform' (a nil value)"

here is the the three local scripts in StarterGui Buttony:

local UIS = game:GetService('UserInputService')
local pressing
local Energy = 90
local player = game.Players.LocalPlayer
local character = player.Character

if not player or not character.Parent then
    character = player.CharacterAdded:wait()
end
done = false
UIS.InputBegan:connect(function(inputObject, gameProcessedEvent)
	if not gameProcessedEvent then
		if inputObject.KeyCode == Enum.KeyCode.C then
			
			pressing = true
			while pressing do
				if done == false then
				_G.FIRE()				
				_G.Squat()
				wait(2)
				done = true
				_G.TransformReady()
				else
				_G.PowerSquat()
				
				wait(5.2)
				Energy = Energy + 1
				end
					end
					end
					_G.GetEnergy(Energy)
			print('Charging....')
	end
	_G.NOFIRE()
	done = false
	_G.CancelTransform()
	end)
	_G.NOFIRE()
	done = false
	_G.CancelTransform()

UIS.InputEnded:connect(function(inputObject, gameProcessedEvent)
	if not gameProcessedEvent then
		if inputObject.KeyCode == Enum.KeyCode.C then
			pressing = false
			print('u stopped pressing :)')
			_G.NOFIRE()
		end
	end
end)

Flame:

local player = game.Players.LocalPlayer
local character = player.Character
local enraged = false
if not character or not character.Parent then
    character = player.CharacterAdded:wait()
end
local torso = character.LowerTorso
local fire = Instance.new("Fire")
fire.Parent = torso
fire.Enabled = false
fire.Heat = 6
fire.Size = 6

local FireOn = false

_G.FIRE = function()
	fire.Enabled = true
	if enraged == false then
	fire.Color = Color3.new(255,255,255)
	fire.SecondaryColor = Color3.new(255,255,255)
	end	
end
_G.Transform = function()
	enraged =true
end
_G.NOFIRE = function()
	if enraged == true then
		
	else
	fire.Enabled = false
	end
end

and finally, Enragements:

local player = game.Players.LocalPlayer
local character = player.Character
local Ready = false
_G.TransformReady = function()
	Ready = true
end
_G.CancelTransform = function()
	Ready = false
end

if not character or not character.Parent then
    character = player.CharacterAdded:wait()
end
local torso = character.LowerTorso
local fire = Instance.new("Fire")
fire.Parent = torso
fire.Enabled = false
fire.Heat = 16
fire.Size = 10
fire.Enabled = false
UIS.InputBegan:connect(function(inputObject, gameProcessedEvent)
	if not gameProcessedEvent then
		if inputObject.KeyCode == Enum.KeyCode.G then
			if Ready == true then
				fire.Enabled = true
				fire.Color = Color3.new(240,0,0)
				fire.SecondaryColor = Color3.new(255,0,0)
			end			
			end
		end

`