diff --git a/src/saml2/assertion.py b/src/saml2/assertion.py
index 1b678b6..4af4d22 100644
--- a/src/saml2/assertion.py
+++ b/src/saml2/assertion.py
@@ -270,7 +270,7 @@ def post_entity_categories(maps, **kwargs):
     restrictions = {}
     try:
         required = [d['friendly_name'].lower() for d in kwargs['required']]
-    except KeyError:
+    except (KeyError, TypeError):
         required = []
 
     if kwargs["mds"]:
diff --git a/src/saml2/server.py b/src/saml2/server.py
index adfc2c3..3032f33 100644
--- a/src/saml2/server.py
+++ b/src/saml2/server.py
@@ -532,7 +532,7 @@ class Server(Entity):
         to_sign = []
 
         if identity:
-            farg = self.update_farg(in_response_to, destination, farg=farg)
+            farg = self.update_farg(in_response_to, sp_entity_id, farg=farg)
 
             _issuer = self._issuer(issuer)
             ast = Assertion(identity)