Login to the OpenSSO console as administrator; by default, amadmin.
Click the Configuration tab.
Click the Global tab.
Click the Common Federation Configuration link.
Enter the appropriate URL as the value for the SAML Error Page URL attribute.
Enter the appropriate binding as the value for the SAML Error Page HTTP Binding attribute.
The default binding is HTTP-POST. You may change this to HTTP-REDIRECT.
Log out of the console.