Sandbox LUA error

Hi, I’m getting this console error on my Sandbox server, and I have no clue at all, what might be causing it:
[LUA][ERROR] lua/matproxy/player_color.lua:43: Tried to use a NULL entity!

  1. GetPlayerColor - [C]:-1
  2. bind - lua/matproxy/player_color.lua:43
    3. unknown - lua/includes/modules/matproxy.lua:56
    [/LUA]
    If you got any idea what might be causing this, that’d be great, as it’s spamming our console.

Edited: Oh yeah, almost forgot. Here is the file player_color.lua, however I have never touched it, so I dunno why it’s causing errors:
[LUA]
– Proxy Example:

– Proxies
– {
– PlayerColor
– {
– resultVar $color2
– }
– }

matproxy.Add(
{
name = “PlayerColor”,

init	=	function( self, mat, values )

	-- Store the name of the variable we want to set
	self.ResultTo = values.resultvar

end,

bind	=	function( self, mat, ent )

	if ( !IsValid( ent ) ) then return end

	--
	-- If entity is a ragdoll try to convert it into the player
	--
	if ( ent:IsRagdoll() ) then
		ent = ent:GetRagdollOwner()
		if ( !IsValid( ent ) ) then return end
	end

	--
	-- If the target ent has a function called GetPlayerColor then use that
	-- The function SHOULD return a Vector with the chosen player's colour.
	--
	-- In sandbox this function is created as a network function, 
	-- in player_sandbox.lua in SetupDataTables
	--
	if ( ent.GetPlayerColor ) then
		local col = ent:GetPlayerColor()
		if ( isvector( col ) ) then
			mat:SetVector( self.ResultTo, col )
		end
	else
		mat:SetVector( self.ResultTo, Vector( 62.0/255.0, 88.0/255.0, 106.0/255.0 ) )
	end

end 

})[/LUA]

What gamemode? When exactly is the error happening?

Sandbox, probably occoured first time today, some users reported it today on my server atleast.
I’ve installed some addons to the server recently, I’ll list them underneath, so you can take a look if it looks like it might be the cause.


Unbreakable tool: http://steamcommunity.com/sharedfiles/filedetails/?id=111158387
Buoyancy Tool: http://steamcommunity.com/sharedfiles/filedetails/?id=104818321
Offset Trails: http://steamcommunity.com/sharedfiles/filedetails/?id=104527283
Smart Painter: http://steamcommunity.com/sharedfiles/filedetails/?id=126566296
AntiSpazzout: http://steamcommunity.com/sharedfiles/filedetails/?id=206320034
Collision Resizer: http://steamcommunity.com/sharedfiles/filedetails/?id=217376234

I’m curious if Smart Painter might be the cause…

I mean at what point exactly it happens? When a player dies or spawn or when?

I don’t know.
But I think, that it might have something to do with when a player dies.
By the way, players can give each other materials and colors on their playermodel.