you don't appear to have escaped the SP ID https://idp.xxxxx.com/idp/profile/SAML2/Unsolicited/SSO?providerId=https://sp.testshib.org/shibboleth-sp try https://idp.xxxxx.com/idp/profile/SAML2/Unsolicited/SSO?providerId=https%3A%2F%2Fsp.testshib.org%2Fshibboleth-sp ? alan