If you have added your DualShield SSO as a SAML claims provider to your ADFS server, then you must add your ADFS as a SAML service provider to your DualShield server.
Otherwise, if you have added your DualShield SSO as a WSFED claims provider to your ADFS server, then you must add your ADFS as a WSFED service provider to your DualShield server.