Character is not a valid member of backpack? what should i do?

so im making a thing where when u touch someone your body parts become yellow. However, the character is the a member of backpack is what the output says and i have no idea what to do. Help.

Here is the script:

wait()
if script.Parent then
	if not script.Parent:IsA("Script") or not script.Parent.Name == "StarterGear" then
		local debris = game:GetService("Debris")
		local backpack = script.Parent
		local player = backpack.Parent
		while player.Character == nil do wait() end
		local character = player.Character
		if character then
			while character:FindFirstChild("Humanoid") == nil do wait() end
			local hum = character:FindFirstChild("Humanoid")

		-- Logia
		local charparts = character:GetChildren()
		for i = 1, #charparts do
			local charpart = charparts[i]
			if charpart:IsA("BasePart") and charpart.Name ~= "Head" then
				charpart.Touched:connect(function(hit)
					if charpart:FindFirstChild("Hide") then return end
					local stop = true
					if hit ~= nil then
						if hit.Parent ~= nil then
							if hit:FindFirstChild("creator") or 		hit.Parent:FindFirstChild("creator") then
								stop = false
							elseif hit.Parent:FindFirstChild("Humanoid") then
								if hit.Parent:FindFirstChild("Humanoid") ~= hum 		then
									stop = false
								end
							end
						end
					end
					if stop then return end
					local hidemesh = Instance.new("SpecialMesh")
					hidemesh.Name = "Hide"
					hidemesh.MeshType = "FileMesh"
					hidemesh.MeshId = ""
					hidemesh.Scale = Vector3.new(0, 0, 0)
					hidemesh.Parent = charpart
					debris:AddItem(hidemesh, 1.5)
					
					local bodyeffect = Instance.new("Part")
					bodyeffect.Name = "BodyEffect"
					bodyeffect.Transparency = 0.4
					bodyeffect.CanCollide = false
					bodyeffect.FormFactor = "Custom"
					bodyeffect.TopSurface = "Smooth"
					bodyeffect.BottomSurface = "Smooth"
					bodyeffect.CFrame = charpart.CFrame
					bodyeffect.BrickColor = BrickColor.new("New Yeller")
					bodyeffect.Size = charpart.Size
					
					local bodeffect = Instance.new("Part")
					bodeffect.Name = "BodyEffect"
					bodeffect.Transparency = 0.4
					bodeffect.CanCollide = false
					bodeffect.FormFactor = "Custom"
					bodeffect.TopSurface = "Smooth"
					bodeffect.BottomSurface = "Smooth"
					bodeffect.CFrame = charpart.CFrame
					bodeffect.BrickColor = BrickColor.new("New Yeller")
					bodeffect.Size = Vector3.new(0.5, 0.5, 0.5)
					
					local msh = Instance.new("SpecialMesh")
					msh.MeshType = "Sphere"
					msh.Scale = Vector3.new(1, 1, 1)
					msh.Parent = bodeffect

					local light = Instance.new("PointLight")
					light.Brightness = 5
					light.Range = 10
					light.Color = Color3.new(251, 255, 0)
					light.Parent = bodyeffect

					bodyeffect.Parent = charpart.Parent



					local weld = Instance.new("ManualWeld")
					weld.Part0 = bodyeffect
					weld.Part1 = charpart
					weld.C1 = charpart.CFrame:inverse() * bodyeffect.CFrame
					weld.Parent = bodyeffect

					debris:AddItem(bodyeffect, 1.5)

					end)
				end
			end
		end
	end
end