--- openflow-2010-10-13-2.h	2015-07-23 09:54:16.328479329 -0700
+++ openflow-2010-10-14-2.h	2015-07-23 09:54:16.332479329 -0700
@@ -943,7 +943,10 @@
                                        * forward to groups. */
     OFPGMFC_WATCH_UNSUPPORTED,        /* This group cannot watch the
                                          watch_port or watch_group specified. */
-    OFPGMFC_LOOP                      /* Group entry would cause a loop. */
+    OFPGMFC_LOOP,                     /* Group entry would cause a loop. */
+    OFPGMFC_UNKNOWN_GROUP,            /* Group not modified because a group
+                                         MODIFY attempted to modify a
+                                         non-existent group. */
 };
 
 /* ofp_error_msg 'code' values for OFPET_PORT_MOD_FAILED.  'data' contains