If a user encounters a 404 Not Found status or a System Error message, check the URL of the request.


404 Not Found
https://sso.idp.local/idp/startSSO.ping&PartnerSpId=sp1&TargetResource=https%3A%2F%2Fapp.sp1.local%2F causes a 404 Not Found error, because the separator between the path of the URL and the first query parameter is incorrect. The correct separator is a question mark ? and not an ampersand&.
System Error
https://sso.idp.local/idp/startSSO.ping?PartnerSpId=sp1?TargetResource=https%3A%2F%2Fapp.sp1.local%2F causes a System Error message, because the second query parameter separators are incorrect. The correct separator is an ampersand & and not a question mark ?.

You must also use ampersands for all subsequent separators between additional query parameters in the URL.

In addition, you must URL-encode query parameter values that contain restricted characters. For information about URL encoding, see, for example, HTML URL-encoding Reference.

For both sample issues, update the URL of the IdP-initiated single sign-on (SSO) to the following URL.