404 error even after SAML single sign on configured between github enterprise and azure AD

[skc949-user]

🏷️ Discussion Type

Bug

Body

you can see error below :

you can see how it is configured in azure entra id:

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[Jamonygr]

A 404 after SAML usually means GitHub cannot map the SAML response back to the expected org/resource, not simply that Entra login failed.

I would check these in order:

1. Make sure you configured the right level: organization SAML vs enterprise SAML. For org-level SAML the common Entra values are:
   • Identifier: https://github.com/orgs/<ORG>
   • Reply URL: https://github.com/orgs/<ORG>/saml/consume
   • Sign-on URL: https://github.com/orgs/<ORG>/sso
2. Confirm the user is assigned to the Entra enterprise app and already has a GitHub org membership/invitation. SAML SSO does not by itself create/onboard a normal GitHub personal account unless you are using Enterprise Managed Users/SCIM.
3. Check the NameID/User ID claim. Keep casing and value stable; email-case changes can cause linked-identity prompts.
4. Test directly from a clean browser session with https://github.com/orgs/<ORG>/sso.
5. If the failure is for an OAuth/GitHub App path, reauthorize the app after SSO is working.

If this only affects one user, remove/relink that user's external SAML identity from the GitHub org side and have them authenticate again.