Value is not a valid member?

Alright this is really giving me a brick wall. Line 30, it's giving me a "Value is not a valid member" error. It's also pointing to the click(Mouse) for some reason. I click - it print prints tower 1 - I click again, it prints tower 2 (BUT does not actually update the CFrame value..) I click again, and it throws this error. I don't know why the second value is refusing to even update. Tower1 and Tower2 are both cframe values. Script is in a gui. (localscript)

I don't know how this manages to print "Tower 2 selected" once without actually updating the value, then breaking. I put the "Local Tower1/2 =" parts IN the function, and that removes the error but for some godforsaken reason, onlyTower1 value updates. What on earth?

local Player = game.Players.LocalPlayer
local Mouse = Player:GetMouse()
local Tool = script.Parent
local RayIgnore = {workspace.RayIgnore, workspace.BasePlate}

local Ready = true

local Tower1 = script.Parent.Tower1
local Tower2 = script.Parent.Tower2

function click()
    local WallType = script.Parent.WallType
    local CanBuild = script.Parent.CanBuild
    local CanPlace = script.Parent.CanPlace


    Mouse.TargetFilter = workspace.Template






    if CanBuild.Value == true and Ready == true then

        if Mouse.Target.Parent.Name == "Tower" and Tower1.Value.p == Vector3.new(0,0,0) then
            Tower1.Value = Mouse.Target.Parent.OriginPart.CFrame
            print("Tower 1 selected")
            print(Tower1)
        else if Mouse.Target.Parent.Name == "Tower" and Tower1.Value.p ~= Vector3.new(0,0,0) and Tower2.Value.p == Vector3.new(0,0,0) and Tower1.Value.p ~= Mouse.Target.Parent.OriginPart.CFrame.p then 
            Tower2 = Mouse.Target.Parent.OriginPart.CFrame
            print("Tower 2 selected")
            CanPlace.Value = true
        else if Mouse.Target.Parent.Name ~= "Tower"  then
            print("Towers cleared")


        end 
        end
        end

    end
end



    Mouse.Button1Down:connect(function()
    click(Mouse)
    end)