What should I do if my phone doesn't work with my Navigo Liberté + contract?

If you notice a malfunction of your phone, go to your Île-de-France Mobilités application, In the "Purchase" menu, under the heading "Contact us":

• Choose "Titles loaded on my phone",
• Then "I have difficulties validating",
• And finally "I have never managed to validate with my phone and I have a Navigo Liberté + pass".