Authentication Error: Unable to Issue Redirect for OAuth 2.0 Transaction

This article explains the cause of the following error. This error occurs when the authorization server cannot complete the authentication flow because it does not know where to redirect the user after the process is complete.

Unable to issue redirect for OAuth 2.0 transaction

• OAuth 2.0
• OpenID Connect (OIDC)
• Authentication Flows

The root cause of this error is a missing or invalid redirect_uri parameter in the initial /authorize request sent from the application to Auth0.

Other potential causes include:

• A typographical error in the client_id or Auth0 domain name.
• Using an incorrect parameter name, such as redirectURL instead of redirect_uri.
• A general system misconfiguration or a temporary service outage.

To resolve this error, verify the application's authentication request and configuration.

1. Check the /authorize Request: Ensure that the initial authentication request from the application includes a redirect_uri parameter with the correct, URL-encoded callback URL.

2. Verify Application Settings:

   • Confirm that the client_id and domain in the request match the values in the Auth0 Dashboard exactly.

   • In the Auth0 Application settings, ensure the URL provided in the redirect_uri parameter is listed in the Allowed Callback URLs field.

3. Inspect Code for Typos: Carefully review the application code to correct any typographical errors in the parameter names (e.g., ensure redirect_uri is used instead of redirectURL).