Coroutine problems - lua

Question

so I'm trying to make a basic GUI animation system in ROBLOX, using individual frames and a loop to put them into an imagelabel.
This is the function:
local playAnimation = coroutine.create(function(anim,pos,tank)
while true do
local animBase = sp.AnimBase:Clone()
animBase.Parent = tank
animBase.Visible = true
animBase.Position = pos -- line that causes the error mentioned below.
local frame = 1
for i = 0, animations[anim]["FrameNum"] do
frame = frame + 1
animBase.Image = animations[anim]["Frames"][frame]
NewWait(.1) --this right here, the wait, interfears with the yield.
if frame >= animations[anim]["FrameNum"] then
pos,anim,tank = coroutine.yield()
break
end
end
animBase:Destroy()
end
end)
There are two main problems with this:
every time it runs, I get this error:
20:41:01.934 - Players.Player1.PlayerGui.ScreenGui.Gui-MAIN:65: bad argument #3 to 'Position' (UDim2 expected, got number)
Although this error doesn't seem to do anything. (eg. stop the script completely)
The line causing the error is marked with a comment.
I've made sure that pos is correct. I even tried printing it before setting it, it prints the correct thing which is:
{0,120},{0,65}
The other main problem is that I can't resume it after using it once. It can run this line multiple times fine:
coroutine.resume(playAnimation,"Cannon Fire",UDim2.new(0,120,0,68-25),tank.Frame)
but it won't run:
if tank2:FindFirstChild("Ammo") and isTouching(ammoFrame,tank2:GetChildren()[3]) then
local lastAmmoPos = ammoFrame.Position
ammoFrame:Destroy()
coroutine.resume(playAnimation,"Explosion",lastAmmoPos-UDim2.new(0,25-(ammoTypes[type]["Size"].X.Offset)/2,0,25),tank.Frame)
tank2:GetChildren()[3]:Destroy()
end
Yes, the if statement is working fine. ammoFrame is destroyed and so is the third child of tank2. The coroutine just won't resume.

Answer 1

Fixed by removing the coroutine completely and wrapping the for loop inside a spawn function.
local playAnimation = function(anim,pos,tank)
local animBase = sp.AnimBase:Clone()
animBase.Parent = tank
animBase.Visible = true
animBase.Position = pos
local frame = 1
spawn(function()
for i = 0, animations[anim]["FrameNum"] do
frame = frame + 1
animBase.Image = animations[anim]["Frames"][frame]
wait(.1) --this right here, the wait, interfears with the yield.
if frame >= animations[anim]["FrameNum"] then
break
end
end
animBase:Destroy()
end)
end