ID4102: An element of an unexpected type was encountered. To support extended types in SAML2 assertions, extend Saml2SecurityTokenHandler. ...

ID4102: An element of an unexpected type was encountered. To support extended types in SAML2 assertions, extend Saml2SecurityTokenHandler.
Expected type name: '{0}'
Expected type namespace: '{1}'
Encountered type name: '{2}'
Encountered type namespace: '{3}'