diff -r c92587ddabcd -r dd7770b97916 SharpLibEar/Action.cs
--- a/SharpLibEar/Action.cs	Thu Aug 18 14:35:50 2016 +0200
+++ b/SharpLibEar/Action.cs	Thu Aug 18 17:13:21 2016 +0200
@@ -25,6 +25,12 @@
         public void Execute()
         {
             Console.WriteLine("Action executing: " + Brief());
+            if (!IsValid())
+            {
+                Console.WriteLine($"WARNING: action invalid, aborting execution.");
+                return;
+            }
+            
             DoExecute();
         }