Problem seems to be triggered in AuthenticationProcessor.redirectToRequiredActions() There is the following comment in the code: public static Response redirectToRequiredActions(KeycloakSession session, RealmModel realm, ClientSessionModel clientSession, UriInfo uriInfo) { // redirect to non-action url so browser refresh button works without reposting past data but with Idp Initiated login to the broker, browser response is No webpage was found for the web address: https://<broker-root>/auth/realms/<realm name>/login-actions/null HTTP ERROR 404 Please advise what is causing this issue? Using Keycloak version 2.5.1 configured as below: 1. SAML client with IDP Initiated SSO URL specified in Keycloak Broker instance 2. SAML Identity Provider setup: First Login Flow: First Broker Login, Post Login Flow: Blank 3. Keycloak Broker metadata configured in external IdP 4. External Idp initiated login results in user created correctly in the broker, SAML attribute mappers work but post broker login redirect completes with 5. No webpage was found for the web address: https://<broker-root>/auth/realms/<realm name>/login-actions/null HTTP ERROR 404