GetChildren error

Hello, My fellas,

I got some weird error when I tried to test my AI script. It says attempt to index nil with 'GetChildren'. I don’t know what’s wrong with the script. Maybe you guys can help me :slight_smile: . Here is the scripts:
KILLER(Script):

for index, bot in pairs(CollectionService:GetTagged("KillerBot")) do
	if bot.Parent == workspace or workspace.Game then
		local killer = Bot:New(bot)
		Bot:Patrol(bot)
	end
end

BOT(ModuleScript)::

function Bot:SetPhysics()
	for index, part in pairs(self.Model:GetChildren()) do
		if part:IsA("BasePart") then
			PhysicsService:SetPartCollisionGroup(part, "KillerBot")
		end
	end
	
	while wait() do
		local success, err = pcall(function()
			self.Model.PrimaryPart:SetNetworkOwner(nil)
		end)
		
		if not success then
			warn("[ERROR]:", err)
		end
	end
end

I’ll appreciate all of your hardwork to help me on this script :slight_smile: .

self.model doesn’t exist, try printing it out.

Bot:SetPhysics()

Where is this instance method being called?

:GetChildren() exists so most likely self.model is not there