I am working on SP side, and each time we receive a SAML 1.1 Artifact
Assertion, we can see in the logs that message:
Why is the user not authenticated?
You need to create a SAML Assertion with an attribute statement in subject that contains a
<SubjectConfirmation> <ConfirmationMethod>urn:oasis:names:tc:SAML:1.0:cm:bearer </ConfirmationMethod> </SubjectConfirmation>
Reason why you get return code 50 (Sm_Api_Reason_FederationUnacceptedMessage) is that the Assertion cannot be consumed and thus, the user not to be authenticated and receive error 500 in browser.