The query string is missing SAMLRequest Stack Trace: at ComponentSpace.SAML2.Bindings.HTTPRedirectBinding.ParseQueryString(String redirectURL, String messageQueryName, XmlElement& samlMessage, String& relayState, String& signatureAlgorithm, String& signature) at ComponentSpace.SAML2.Bindings.HTTPRedirectBinding.ReceiveRequest(HttpRequest httpRequest, XmlElement& samlMessage, String& relayState, String& signatureAlgorithm, String& signature) at Abila.CS.AddOns.SAML2.IdentityProvider.SSOService.ReceiveAuthnRequest() at Abila.CS.AddOns.SAML2.IdentityProvider.SSOService.ReceiveSSORequest() at Abila.CS.AddOns.SAML2.IdentityProvider.SSOService.ProcessPageLoad() at Abila.CS.AddOns.SAML2.IdentityProvider.SSOService.Page_Load(Object sender, EventArgs e)