Auth0 Embedded Login With Passwordless Connection Fails

A Single Page Application with an embedded login form using Auth0.js is now trying to authenticate users with an email passwordless connection.

Some users see this error in the browser address bar after entering the OTP code sent to their email.

https://APPLICATION_CALLBACK_URL?error=server_error&error_description=Unable%20to%20configure%20verification%20page.&state=

After enabling a custom domain with the same top-level domain as their application and updating the Auth0.js library to the latest version, the users started seeing this error upon entering the code:

Something Went Wrong

The link must be opened on the same device and browser from which you submitted your email address.

• Auth0
• Embedded Login
• Passwordless Connection

An old version of the SDK was used, and the passwordless flow was started on a different domain. To make it work from localhost, a tenant flag must be enabled.

Follow the steps below to resolve the connection error:

1. Make sure to use the latest version of Auth0.js.
2. With the Management API call the Update tenant settings endpoint with this payload:

   {"universal_login":{"passwordless":{"allow_magiclink_verify_without_session":true}}}

Review Auth0.js v9 Reference for more details.