"multiple Points" Error?

--[[
	Xyexs	   Smart mining turtle(SMT) 3.0
Set up:
Get this file from pastebin
Run the program
Follow the instructions
Change log:
3.0.0
Added change log.
Rewritten (mostly, copied a bit).
Added a nifty interface.
Fixed a common problem that caused it to lose its position after chunk reload at times.
Prettied up the code.
]]
--Variables------
local width = nil
local depth = nil
local VERSION = "3.0.0"
local moveArray = {}--Contains all movements
local noteArray = {"","","",""}--Contains all notifications
local lastFuelLevel = nil -- What the fuel level was at before reboot
local x = nil
local y = nil--The turtles coordinates(Y is reversed)
local z = nil
local facing = nil
local shouldBeAtX ={}
local shouldBeAtY ={}--reversed
local shouldBeAtZ ={}
local shouldBeFacing ={}
local genIndex = 0
local oldFuelLevel = nil -- session persistence things
local junkSlots = nil
local selectedSlot = 1 --Umhh.... do I need to comment here?
-----------------

--Functions------
--File functions
function save()-- Saves crucial variables to a file ( this is required for session persistence)
local w = fs.open("/miningData","w")
	w.writeLine(x)
w.writeLine(y)
w.writeLine(z)
w.writeLine(isAtIndex)
w.writeLine(width)
w.writeLine(depth)
w.writeLine(turtle.getFuelLevel())
w.writeLine(junkSlots)
w.close()
end
function load()--Loads saved data
if fs.exists("/miningData") then
  local r = fs.open("/miningData","r")
  x = r.readLine()
  y = r.readLine()
  z = r.readLine()
  isAtIndex = r.readLine()
  width = r.readLine()
  depth = r.readLine()
  oldFuelLevel = r.readLine()
  junkSlots = r.readLine()
  r.close()
else
  term.clear()
  term.setCursorPos(1,1)
  print("Hi, let's set up before I start mining!\n\n")
  print("What is the turtles current y coordinate?")
  depth = read()
  while type(depth) ~= number do
   print("Umh... That's not a number- try again!")
   depth=read()
  end
  depth = tonumber(depth) - 4
  print("Awesome! Now how wide do you want it? It's a square so... diameter?")
  width = read()
  while type(width) ~= number do
   print("Umh... That's not a number- try again!")
   width=read()
  end
  width = tonumber(width)
  print("\nOne more thing, put blocks you want me to ignore in slots 1-4 and press any key :D/>/>/>")
  os.pullEvent("key")
  for i = 1,4 do
   if turtle.getItemCount(i) ~= 0 then
	junkSlots = junkSlots + 1
   end
  end
  print("Okie , I'll start mining now")
  sleep(0.5)
end
end
--UI functions
function updateProgressBar()--Resets and prints the progress bar
local percentage = math.ceil(isAtIndex / #moveArray) --Stores the percentage completed, 20 % would be 0.20
term.setCursorPos(2,2)
term.write("[								  ]")
term.setCursorPos(3,2)
for i = 1, math.ceil(percentage * 34) do
  term.write("X")
end
term.setCursorPos(17,1)
term.write("	 ")
term.setCursorPos(17,1)
term.write(percentage * 100.." %")
end
function updateNotes()--Updates the notifications
for i = 6,12 do
  term.setCursorPos(19,i)
  term.write("					")
end
local noteCounter = 1
for i = 20,26, +2 do
  term.setCursorPos(i,6)
  term.write(noteArray[noteCounter])
  noteCounter = noteCounter + 1
end
end
function updateScreen() -- Updates the UI
term.clear()
updateProgressBar()
term.setCursorPos(1,4)
print("-----------------v---------------------\n				 -\n				 -\n				 -\n				 -\n				 -\n				 -\n				 -\n				 ---------------------\n				 - SMT "..version.." by Xyexs")
updateProgressBar()
updateNotes()
end
function addNote(local note) -- Adds a notification with a maximum of 21 chars
noteArray[3] = noteArray[2]
noteArray[2] = noteArray[1]
noteArray[1] = note
updateNotes()
end
--Movement etc. functions
function face(local direction)
	local testFacing = facing
	local leftCounter= 0
	local rightCounter= 0
	while testFacing ~= direction do
		testFacing = (testFacing - 1) %4
		leftCounter = leftCounter + 1
	end
	testFacing =facing
	while testFacing ~= direction do
		testFacing = (testFacing + 1) %4
		rightCounter = rightCounter + 1
	end
	while facing ~= direction do
		if leftCounter > rightCounter then
			right()
		else
   left()
		end
	end
end
function goto(local goX,goY,goZ,goFace) -- moves to the specified location
if goZ ~= z then
  face(1)
  while y ~= 1 do
   forw()
  end
  face(2)
  while x ~= 1 do
   forw()
  end
  while y ~= goY do
   if y < goY then
	up()
   elseif y > go then
	down()
   else
	term.clear()
	term.setCursorPos(1,1)
	error("Tell Xyexs his logic is not logical :P/>/>/>")
   end
  end
end
face(0)
while x ~= goX do
  forw()
end
face(3)
while y ~= goY do
  forw()
end
face(goFace)
end
function drop(local fslot,lslot) -- Drops the inventory content from fslot to lslot
for local i=fslot,lslot do
  turtle.select(i)
  if turtle.drop() == false and turtle.getItemCount(i) ~= 0then
   addNote("Can't drop- full?")
  end
  while turtle.drop() == false and turtle.getItemCount(i) ~= 0 do
   sleep(2)
  end
end
end
function refuel() -- checks the fuel level and returns to surface if it needs more fuel
--Meh, ill write this later :D/>/>/>... right now I just want to get a test version out
end
function dig()
turtle.dig()
end
function digUp()
turtle.digUp()
end
function digDown()
turtle.digDown()
end
function left()
turtle.left()
facing = (facing - 1) % 4
end
function right()
turtle.right()
facing = (facing + 1) % 4
end
function forw()
if turtle.forward() == false then -- this is just anti-spamming
  addNote("Trouble moving...")
  while turtle.forward() == false do
   dig()
  end
end
if facing == 0 then
  x = x + 1
elseif facing == 1 then
  y = y - 1
elseif facing == 2 then
  x = x - 1
elseif facing == 3 then
  y = y + 1
else
  term.clear()
  term.setCursorPos(1,1)
  error("ERROR! INVALID FACING VARIABLE, contact Xyexs immediately! (:o/>/>/>, dramatic)")
end
refuel()
end
function up()
if turtle.up() == false then
  addNote("Trouble moving up")
  while turtle.up() == false do
   digUp()
  end
end
z = z - 1
refuel()
end
function down()
if turtle.down() == false then
  addNote("Trouble moving down")
  while turtle.down() == false do
   digDown()
  end
end
z = z + 1
refuel()
end
function compareDig()
if junkSlots > 0 then
  local isJunkDown = false
  local isJunkUp = false
  if selectedSlot == 1 then
   for i = 1 , junkSlots do
	turtle.select(i)
	if turtle.compareUp()== true then
	 isJunkUp = true
	end
	if turtle.compareDown()== true then
	 isJunkDown = true
	end
   end
  else
   for i = junkSlots , 1, -1 do
	turtle.select(i)
	selectedSlot = i
	if turtle.compareUp()== true then
	 isJunkUp = true
	end
	if turtle.compareDown()== true then
	 isJunkDown = true
	end
   end
  end
  if isJunkUp == false then
   digUp()
  end
  if isJunkDown == false then
   digDown()
  end
else
  digUp()
  digDown()
end
end
--Path generating functions
function insertGen(local shouldX,shouldY,shouldZ,shouldFace,move)--inserts the variables to the correct arrays
genIndex = genIndex + 1
shouldBeAtX[genIndex] = shouldX
shouldBeAtY[genIndex] = shouldY
shouldBeAtZ[genIndex] = shouldZ
shouldBeFacing[genIndex] = shouldFace
moveArray[genIndex] = move
end
function genDig()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex],shouldBeFacing[genIndex],dig)
end
function genDigUp()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex],shouldBeFacing[genIndex],digUp)
end
function genDigDown()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex],shouldBeFacing[genIndex],digDown)
end
function genCompareDig()
if moveArray[genIndex] ~= nil then -- Because this generates first I had to do this :D/>/>/>
  insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex],shouldBeFacing[genIndex],compareDig)
else
  insertGen(1,1,1,0,compareDig)
end
end
function genRight()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex],(shouldBeFacing[genIndex]+1) % 4,right)
end
function genLeft()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex],(shouldBeFacing[genIndex]+1) % 4,left)
end
function genForw()
if shouldBeFacing[genIndex] == 0 then
  insertGen(shouldBeAtX[genIndex] + 1,shouldBeAtY[genIndex],shouldBeAtZ[genIndex],shouldBeFacing[genIndex],forw)
elseif shouldBeFacing[genIndex] == 1 then
  insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex] - 1,shouldBeAtZ[genIndex],shouldBeFacing[genIndex],forw)
elseif shouldBeFacing[genIndex] == 2 then
  insertGen(shouldBeAtX[genIndex] - 1,shouldBeAtY[genIndex],shouldBeAtZ[genIndex],shouldBeFacing[genIndex],forw)
elseif shouldBeFacing[genIndex] == 3 then
  insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex] + 1,shouldBeAtZ[genIndex],shouldBeFacing[genIndex],forw)
else
  term.clear()
  term.setCursorPos(1,1)
  error("ERROR! INVALID (gen)FACING VARIABLE, contact Xyexs immediately! (:o/>/>/>, dramatic)")
end
end
function genDown()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex] + 1,shouldBeFacing[genIndex],down)
end
function genUp()
insertGen(shouldBeAtX[genIndex],shouldBeAtY[genIndex],shouldBeAtZ[genIndex] - 1,shouldBeFacing[genIndex],down)
end
function genDigRow()
for i = 1, width - 1 do
  genCompareDig()
  genDig()
  genForw()
end
end
function genDigLayer() -- should be more loops in this one... just cant find a good solution to that...
if width % 2 == 0 then
  for i = 1 , width / 2 - 1 do
   genDigRow()
   genCompareDig()
   genLeft()
   dig()
   genForw()
   genLeft()
   genDigRow()
   genCompareDig()
   genRight()
   dig()
   genForw()
   genRight()
  end
  genDigRow()
  genCompareDig()
  genLeft()
  dig()
  genForw()
  genLeft()
  genDigRow()
  genCompareDig()
  genLeft()
  for i = 1, size-1 do
   genForw()
  end
  genLeft()
else
  for i = 1, (size - 1)/2 do
   genDigRow()
   genCompareDig()
   genLeft()
   dig()
   genForw()
   genLeft()
   genDigRow()
   genCompareDig()
   genRight()
   dig()
   genForw()
   genRight()
  end
  genDigRow()
  genCompareDig()
  genRight()
  while y ~= 1 do
   genForw()
  end
  genRight()
  while x ~= 1 do
   genForw()
  end
  genLeft()
  genLeft()
end
end
function genPath()
addNote("Generating path...")
for i = 1, depth do
  genDigLayer()
end
for i = 1, 3 do
  genDown()
  if shouldBeAtY == depth then
   break
  end
end
end
-----------------
--Program--------
load()
updateScreen()
genPath()
if turtle.getFuelLevel() ~= oldFuelLevel then
goto(shouldBeAtX[isAtIndex],shouldBeAtY[isAtIndex],shouldBeAtZ[isAtIndex],shouldFace[isAtIndex])
end
repeat
moveArray[isAtIndex]()
isAtIndex = isAtIndex + 1
save()
updateProgressBar()
until isAtIndex == #moveArray
updateProgressBar()
fs.delete("/miningData")
fs.delete("/startup")
goto(1,1,1,2)
drop(1,16)
face(0)
term.clear()
term.setCursorPos(1,1)
print("If you liked ... or didn't like .. the script, leave a comment and let me know!\n\n				  // Xyexs")
-----------------