Improve auto response for non-approved ADFS accounts during Portal sign in

Idea created by dillec on Dec 13, 2016

    Currently, when a user who is not authorized to access Portal for ArcGIS attempts to sign in using the ADFS option, Portal extends an uninformed response.  It says "Unable to login using Idp Error parsing 'NAME_ID' from SAML response". It would be a nice feature if administrators could customize a message that informs rejected users that they need to contact the helpdesk and request access.