Error Message: Please retry downloading this title... sign out and sign in with your updated username/password

This error message can normally be resolved by signing out and then back into the Audible for Android app.

1. Tap the left navigation menu. 
2. Tap Settings.
3. Tap Sign Out [Amazon email address or Audible username].
   
4. Tap I'm Already Using Audible. Sign in on the Audible Welcome Screen.
5. Enter your Amazon sign-in credentials.
Tip:If you use a Username for your account, tap Sign in with your Audible Username toward the bottom of the screen.
6. Tap Sign in.
After signing back into your app, go back to My Library and attempt to download the Audiobook again.