Error AADSTS75005 - The request is not a valid Saml2 protocol message

This article describes a problem in which you receive the error message "Error AADSTS75005 - The request is not a valid Saml2 protocol message." when you try to sign into an apapplication that has been integrated with Microsoft Entra ID.

Symptoms

You receive error AADSTS75005 when trying to sign into an application that has been set up to use Microsoft Entra ID for identity management using SAML-based SSO.

Cause

Microsoft Entra ID doesn't support the SAML request sent by the application for single sign-on. Some common issues are:

• Missing required fields in the SAML request.
• SAML request encoded method.

Resolution

1. Capture the SAML request. Follow the tutorial How to debug SAML-based single sign-on to applications in Microsoft Entra ID to learn how to capture the SAML request.
2. Contact the application vendor and share the following info:
   • SAML request
   • Microsoft Entra Single Sign-on SAML protocol requirements

The application vendor should validate that they support the Microsoft Entra SAML implementation for single sign-on.

More Information

For a full list of Active Directory Authentication and authorization error codes, see Microsoft Entra authentication and authorization error codes

Contact us for help

If you have questions or need help, create a support request, or ask Azure community support. You can also submit product feedback to Azure feedback community.