* Fixed that converted mana costs for stack objects were not always calculated correctly (e.g. a Mental Misstep could counter a Cahlice of the Coid with X=1).

Mage/src/mage/game/stack/StackAbility.java

@@ -208,6 +208,14 @@ public class StackAbility implements StackObject, Ability {
         return emptyCosts;
     }
 
+    @Override
+    public int getConvertedManaCost() {
+        // Activated abilities have an "activation cost" but they don't have a characteristic related to that while on the stack. 
+        // There are certain effects that interact with the cost to activate an ability (e.g., Training Grounds, Power Artifact)
+        // but nothing that looks for that quality of an ability once it's on the stack. 
+        return 0;
+    }
+
     @Override
     public Effects getEffects() {
         return ability.getEffects();