combat manage null check

src/engine/gameManager/CombatManager.java

@@ -119,6 +119,9 @@ public enum CombatManager {
 
     public static void processAttack(AbstractCharacter attacker, AbstractWorldObject target, mbEnums.EquipSlotType slot) {
 
+        if(slot == null || target == null || attacker == null)
+            return;
+
         if (attacker.getObjectType().equals(mbEnums.GameObjectType.PlayerCharacter)) {
             if (!attacker.isCombat())
                 return;