Printer Error On Explotion

[Gomez]

I have a printer that changes color rapidly with a 0.4 timer. When the printer explodes, an error comes up regarding a null entity. How do I fix this?

[ERROR] addons/tierprinters/lua/entities/tier5/cl_init.lua:17: Tried to use a NULL entity!
1. SetColor - [C]:-1
2. unknown - addons/tierprinters/lua/entities/tier5/cl_init.lua:17

[url]http://pastie.org/10339734[/url]

[DaRkWoRlD1337]

when it explodes, stop the timer. this happened me a lot, easy to fix.

[Gomez]

[QUOTE=DaRkWoRlD1337;48416722]when it explodes, stop the timer. this happened me a lot, easy to fix.[/QUOTE]

How do I do this?

[editline]9th August 2015[/editline]

include("shared.lua")

function ENT:Initialize()
end

local nextColorChange = 0

function ENT:Draw()

self:DrawModel()

if SysTime() >= nextColorChange then

nextColorChange = SysTime() + 0.4 -- 0.4 means every 0.4 seconds it will change colour

local col = Color( math.random( 0, 255 ), math.random( 0, 255 ), math.random( 0, 255 ) )
self:SetColor( col )

end

local Pos = self:GetPos()
local Ang = self:GetAngles()

local owner = self:Getowning_ent()
owner = (IsValid(owner) and owner:Nick()) or "unknown"

txt1 = "Nuclear Printer"
txt2 = "$" ..self:GetNWInt("PrintA")

surface.SetFont("HUDNumber5")
local TextWidth = surface.GetTextSize(txt1)
local TextWidth2 = surface.GetTextSize(txt2)
local TextWidth3 = surface.GetTextSize(owner)

Ang:RotateAroundAxis(Ang:Up(), 90)

cam.Start3D2D(Pos + Ang:Up() * 4.5, Ang, 0.11)
draw.WordBox(2, -TextWidth3*0.5, -78, owner, "HUDNumber5", Color(0, 0, 0, 100), Color(255,255,255,255))
draw.WordBox(2, -TextWidth*0.5, -30, txt1, "HUDNumber5", Color(0, 0, 0, 100), Color(255,255,255,255))
draw.WordBox(2, -TextWidth2*0.5, 18, txt2, "HUDNumber5", Color(0, 0, 0, 100), Color(255,255,255,255))
cam.End3D2D()
end

function ENT:Think()
end