Troubleshooting Auth0 Login Errors on WordPress no verifier and no verification page

This article addresses two common login errors you might encounter when using Auth0 for user authentication on your WordPress site:

Error 1: There was a problem with your log in: No verifier returned from client. [error code: invalid_request]

This error indicates a communication issue between your WordPress site and Auth0 during login. Here's how to troubleshoot it:

• Check Configuration: Verify that the Domain and Client ID in the "Login by Auth0" plugin match exactly with the ones you set up in your Auth0 application for your WordPress site.

• Reinstall and Reconfigure: Try reinstalling the "Login by Auth0" plugin and reconfigure it with the correct details from your Auth0 application.

• Review Logs: Enable debug logging in both WordPress and Auth0. This can provide more specific details about the error during communication.

Error 2: There was a problem with your log in: Unable to configure verification page. [error code: server_error]

This error points towards an issue during the verification stage, often caused by cross-origin restrictions. Here's how to address it:

• Browser Compatibility: Test login with different browsers like Chrome or Firefox. Safari, especially with stricter privacy settings, might block cookies needed for verification.

• Cross-Origin Issue: This occurs when your WordPress site and Auth0 domain have different top-level domains (e.g., yoursite.com and auth0.com). Browsers might block cookies needed for verification. Here are solutions:

  • Enable Custom Domains (if possible): Upgrading your Auth0 plan allows using a custom domain matching your WordPress site (e.g., [invalid URL removed]). This eliminates the cross-origin issue and allows first-party cookies.

  • Hosted Login Page: Consider using Auth0's hosted login page. This page avoids the cross-origin challenge but might offer less customization.

• Plugin Conflicts: Disable other plugins temporarily to see if they interfere with Auth0's verification process.

For further information you can also check in the sidebar Monitoring > Logs

Additional Resources:

• Login by Auth0 Plugin Installation: https://auth0.com/docs/customize/integrations/cms/wordpress-plugin/integrate-with-wordpress

• Troubleshooting Login by Auth0: https://auth0.com/docs/customize/integrations/cms/wordpress-plugin/troubleshoot-login-by-auth0

• Auth0 Custom Domains: https://auth0.com/docs/customize/custom-domains

By following these steps and referring to the resources, you should be able to identify and fix the login errors you encounter when using Auth0 with your WordPress site.