MIX Release fails with ejabberd

Hi Forum,

I’m using the Embedded Ejabberd in an Elixir application. everything works perfectly on dev.

When I try to MIX_ENV=prod mix release I get this error:

** (Mix) :p1_utils is listed both as a regular application and as an included application.

This is the content of my Mix file:

defmodule Mantu.MixProject do
  use Mix.Project

  def project do
    [
      app: :mantu,
      version: "0.1.0",
      elixir: "~> 1.10",
      elixirc_paths: ["lib"],
      start_permanent: Mix.env() == :prod,
      deps: deps()
    ]
  end

  # Run "mix help compile.app" to learn about applications.
  def application do
    [
      extra_applications: [:logger]
    ]
  end

  # Run "mix help deps" to learn about dependencies.
  defp deps do
    [
      {:ejabberd, "~> 20.7"}
    ]
  end
end

Would appreciate some help,
Best regards,
Haim