Don't know exactly when this assertion error happens, but I still see reports from people. So ultimately delegating this to the Hudson object.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@10447 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/Functions.java

@@ -470,7 +470,7 @@ public class Functions {
                     return;
                 }
             }
-            throw new AssertionError(); // ancestor must include Hudson, which is AccessControlled.
+            checkPermission(Hudson.getInstance(),permission);
         }
     }