Index: undo_old.c
===================================================================
--- undo_old.c	(revision 11016)
+++ undo_old.c	(revision 11017)
@@ -431,7 +431,7 @@
 		return (pcb_true);
 	}
 	pcb_message(PCB_MSG_ERROR, "hace Internal error: Can't find ID %d type %08x\n", Entry->ID, Entry->Kind);
-	pcb_message(PCB_MSG_ERROR, "for UndoFlag Operation. Previous flags: %s\n", pcb_strflg_f2s(Entry->Data.Flags, 0));
+	pcb_message(PCB_MSG_ERROR, "for UndoFlag Operation. Previous flags: %s\n", pcb_strflg_f2s(Entry->Data.Flags, 0, NULL));
 	return (pcb_false);
 }