SSO login fails with message "The AuthnRequest with AuthnContexts is not supported"


SSO login fails and the SAML Response returns a StatusCode "Responder" with the message "The AuthnRequest with AuthnContexts is not supported!"

<Response ID="xxx" InResponseTo="SNCxxx" IssueInstant="2019-08-13T19:27:46Z" Version="2.0" xmlns="urn:oasis:names:tc:SAML:2.0:protocol">
    <ns1:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity" xmlns:ns1="urn:oasis:names:tc:SAML:2.0:assertion">IdP</ns1:Issuer>
        <StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Responder">
            <StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:RequestUnsupported"/>
        <StatusMessage>The AuthnRequest with AuthnContexts is not supported!</StatusMessage>


The Identity Provider (IdP) does not support Service Providers sending AuthnContextClass along with AuthnRequests.


On the IdP form, uncheck "Create AuthnContextClass" and test the connection. 

This will no longer send the AuthnContextClass along with the AuthnRequest and will let the IdP choose the authentication context class.