Program: 44373
Project: 44373
Buggy source:
public void registerCreatureDeath(CreatureKilledByPlayerEvent event){
  if (shouldClearDefaultDrops) {
    event.getDrops().clear();
    event.setDroppedExp(0);
  }
  if (event.getKiller().getItemInHand().getType().equals(Material.BOW) && !hasBowRewards) {
    messageManager.basicMessage(messageManager.noBowRewardMessage,event.getKiller());
    return;
  }
  if (EntityUtils.isUnderSeaLevel(event.getKiller()) && !canHuntUnderSeaLevel) {
    messageManager.basicMessage(messageManager.noBowRewardMessage,event.getKiller());
    return;
  }
  if (event.usedTamedCreature() && !isWolverineMode) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (EntityUtils.isOwner(event.getKiller(),event.getKilledCreature())) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (DependencyUtils.hasMobArena() && DependencyUtils.getMobArenaHandler().isPlayerInArena(event.getKiller()) && !hasMobArenaRewards) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (!hasCreativeModeRewards && event.getKiller().getGameMode() == GameMode.CREATIVE) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (!canCampSpawner && (campByDistance || campByEntity)) {
    if ((campByEntity && isSpawnerMob(event.getKilledCreature())) || (campByDistance && (EntityUtils.isNearSpawner(event.getKiller(),campRadius) || EntityUtils.isNearSpawner(event.getKilledCreature(),campRadius)))) {
      if (shouldClearCampDrops) {
        event.getDrops().clear();
        event.setDroppedExp(0);
      }
      messageManager.spawnerMessage(messageManager.noCampMessage,event.getKiller());
      ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
      return;
    }
  }
  if (!DependencyUtils.hasPermission(event.getKiller(),"String_Node_Str" + RewardType.fromEntity(event.getKilledCreature()).getName())) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str"+ RewardType.fromEntity(event.getKilledCreature()).getName());
    return;
  }
  if (hasReward(event.getKilledCreature())) {
    Reward reward=getRewardForEntity(event.getKilledCreature());
    if (reward.hasExp()) {
      event.setDroppedExp(reward.getExp().getAmount());
    }
    registerReward(event.getKiller(),reward,event.getWeaponName());
    try {
      List<ItemStack> rewardDrops=reward.getDropAmounts(isFixedDrops);
      if (!rewardDrops.isEmpty()) {
        if (!event.getDrops().isEmpty() && shouldOverrideDrops) {
          event.getDrops().clear();
        }
        event.getDrops().addAll(rewardDrops);
      }
    }
 catch (    IllegalArgumentException e) {
      ECLogger.getInstance().warning(e.getMessage());
    }
  }
}

Fixed version (ground truth):
public void registerCreatureDeath(CreatureKilledByPlayerEvent event){
  if (shouldClearDefaultDrops) {
    event.getDrops().clear();
    event.setDroppedExp(0);
  }
  if (EntityUtils.getItemTypeInHand(event.getKiller()).equals(Material.BOW) && !hasBowRewards) {
    messageManager.basicMessage(messageManager.noBowRewardMessage,event.getKiller());
    return;
  }
  if (EntityUtils.isUnderSeaLevel(event.getKiller()) && !canHuntUnderSeaLevel) {
    messageManager.basicMessage(messageManager.noBowRewardMessage,event.getKiller());
    return;
  }
  if (event.usedTamedCreature() && !isWolverineMode) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (EntityUtils.isOwner(event.getKiller(),event.getKilledCreature())) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (DependencyUtils.hasMobArena() && DependencyUtils.getMobArenaHandler().isPlayerInArena(event.getKiller()) && !hasMobArenaRewards) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (!hasCreativeModeRewards && event.getKiller().getGameMode() == GameMode.CREATIVE) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
    return;
  }
  if (!canCampSpawner && (campByDistance || campByEntity)) {
    if ((campByEntity && isSpawnerMob(event.getKilledCreature())) || (campByDistance && (EntityUtils.isNearSpawner(event.getKiller(),campRadius) || EntityUtils.isNearSpawner(event.getKilledCreature(),campRadius)))) {
      if (shouldClearCampDrops) {
        event.getDrops().clear();
        event.setDroppedExp(0);
      }
      messageManager.spawnerMessage(messageManager.noCampMessage,event.getKiller());
      ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str");
      return;
    }
  }
  if (!DependencyUtils.hasPermission(event.getKiller(),"String_Node_Str" + RewardType.fromEntity(event.getKilledCreature()).getName())) {
    ECLogger.getInstance().debug("String_Node_Str" + event.getKiller().getName() + "String_Node_Str"+ RewardType.fromEntity(event.getKilledCreature()).getName());
    return;
  }
  if (hasReward(event.getKilledCreature())) {
    Reward reward=getRewardForEntity(event.getKilledCreature());
    if (reward.hasExp()) {
      event.setDroppedExp(reward.getExp().getAmount());
    }
    registerReward(event.getKiller(),reward,event.getWeaponName());
    try {
      List<ItemStack> rewardDrops=reward.getDropAmounts(isFixedDrops);
      if (!rewardDrops.isEmpty()) {
        if (!event.getDrops().isEmpty() && shouldOverrideDrops) {
          event.getDrops().clear();
        }
        event.getDrops().addAll(rewardDrops);
      }
    }
 catch (    IllegalArgumentException e) {
      ECLogger.getInstance().warning(e.getMessage());
    }
  }
}