Index: /trunk/grails-app/controllers/LoginController.groovy
===================================================================
--- /trunk/grails-app/controllers/LoginController.groovy	(revision 171)
+++ /trunk/grails-app/controllers/LoginController.groovy	(revision 172)
@@ -150,6 +150,6 @@
                 msg = "[$username] is disabled."
             }
-            else if (person.authorities.isEmpty()) {
-                msg = "[$username] has no GrantedAuthority."
+            else if (person?.authorities?.isEmpty()) {
+                msg = "[$username] has no granted authority."
             }
             else {