Fix IllegalArgumentException

✅ Solution

The "IllegalArgumentException" in Keycloak SAML processing often stems from malformed or invalid SAML requests/responses, particularly related to XML parsing or signature validation. To fix this, carefully validate the SAML configuration within Keycloak, including entity IDs, signature algorithms, and ensure the incoming SAML documents conform strictly to the SAML specification. Also, update to the latest Keycloak version with updated XML security dependencies, if possible, as it might contain necessary bug fixes.