31301: Registration error

This error occurs when registration for incoming call push notifications fails. Set up your push certificate in the Console, register the app with Voice.register(...), and use an Access Token that includes a VoiceGrant and a non-empty identity.

• Your app is not set up with a push certificate in the Console, or it is not registering for incoming calls with Voice.register(...).
• The Access Token does not include a VoiceGrant, or the API key and secret used to generate the token are incorrect.
• The device token has changed, or the registration has not been refreshed in more than 6 months.
• The Access Token does not include a non-empty identity.

• Set up the push certificate in the Console and call Voice.register(...) when the app launches so the device can receive incoming calls.
• Generate the Access Token with a VoiceGrant, and verify that you are using the correct API key and secret pair.
• Re-register the device token whenever it changes, and register again if Voice.register(...) was last called more than 6 months ago.
• Make sure the Access Token includes a non-empty identity.

• Voice Android SDK FAQ
• Voice Mobile SDKs: Best Practices