AddAccessory should be passed a valid Accessory object.?

I'm trying to add custom accessories added to the player onced joined when in specific teams. The problem sometimes shows this error and the accessories don't show up. On line 22, I the part removes the players custom accessories then replaced with the the team accessories. So why doesn't it work? Thanks.

local ss = game:GetService("ServerStorage")

local function playerAdded(player)
    player.CharacterAdded:Connect(function(char)    

        local vest = nil
        local hat = nil
        local leg = nil

        if player.Team.Name == "Chief" then

            vest = ss.Uniforms.Chief:WaitForChild("Vest"):Clone()
            hat = ss.Uniforms.Chief:WaitForChild("Hat"):Clone()
            leg = ss.Uniforms.Chief:WaitForChild("Leg"):Clone()

         elseif player.Team.Name == "---" then
            vest = ss:WaitForChild("---"):Clone()
        end

        local hum = char:WaitForChild("Humanoid")

        for i, v in pairs(char:GetChildren()) do
            if v:IsA("Accessory") then
                v:Destroy()
            end
        end

        wait()

        --[[hum:AddAccessory(vest)

        hum:AddAccessory(hat)

        hum:AddAccessory(leg)]]

hum:AddAccessory(vest, hat, leg)

    end)
end

game.Players.PlayerAdded:Connect(playerAdded)