Issue with getting character

im currently getting an error message:

not sure why this happened? when I used the exact same variable for a dif module script

local module = {}
module.WeaponEquip = function(player,WeaponName)
	local character = player.Character
	for i,v in character:GetChildren() do
		if v.Name == WeaponName then
			print("works")
			v.CASEPart.Basic_Handle.Transparency = 1
		end
	end
end

return module

my local script is

local tool = script.Parent


tool.Equipped:Connect(function()
	print("works?")
	local module = require(game:GetService("ReplicatedStorage").Modules.WeaponModule)
	local Name = script.Parent.KatanaName.Value
	module.WeaponEquip(player,Name)
end)

are you sure you defined what player is? in the localscript?