Program: 187723
Project: 187723
Buggy source:
public void DropTimer(){
  if (isThere == true) {
    DropTimer=cb.Plugin.getServer().getScheduler().scheduleSyncRepeatingTask(cb.Plugin,new Runnable(){
      public void run(){
        if (isThere == false || isDead == true || getPlayer() == null) {
          StopDropTimer();
        }
 else {
          if (getPlayer() != null) {
            try {
              for (              Entity e : MyWolf.getWorld().getEntities()) {
                if (e instanceof Item) {
                  Item item=(Item)e;
                  Vector distance=getLocation().toVector().add(new Vector(0.5,0,0.5)).subtract(item.getLocation().toVector());
                  if (distance.lengthSquared() < 1.0 * cb.cv.WolfPickupRange * cb.cv.WolfPickupRange + 1) {
                    int amountleft=Inventory.addItem(item);
                    if (amountleft == 0) {
                      e.remove();
                    }
 else {
                      if (item.getItemStack().getAmount() > amountleft) {
                        item.getItemStack().setAmount(amountleft);
                      }
                    }
                  }
                }
              }
            }
 catch (            Exception e) {
              System.out.println("String_Node_Str");
              e.printStackTrace();
            }
          }
 else {
            StopDropTimer();
          }
        }
      }
    }
,0L,20L);
  }
}

Fixed version (ground truth):
public void DropTimer(){
  if (isThere == true) {
    DropTimer=cb.Plugin.getServer().getScheduler().scheduleSyncRepeatingTask(cb.Plugin,new Runnable(){
      public void run(){
        if (isThere == false || isDead == true || getPlayer() == null) {
          StopDropTimer();
        }
 else {
          if (getPlayer() != null) {
            try {
              for (              Entity e : MyWolf.getWorld().getEntities()) {
                if (e instanceof Item) {
                  Item item=(Item)e;
                  Vector distance=getLocation().toVector().add(new Vector(0.5,0,0.5)).subtract(item.getLocation().toVector());
                  if (distance.lengthSquared() < 1.0 * cb.cv.WolfPickupRange * cb.cv.WolfPickupRange + 1) {
                    int amountleft=Inventory1.addItem(item);
                    if (amountleft == 0) {
                      e.remove();
                    }
 else {
                      if (item.getItemStack().getAmount() > amountleft) {
                        item.getItemStack().setAmount(amountleft);
                      }
                      if (InventoryMode == InventoryType.LARGE) {
                        amountleft=Inventory2.addItem(item);
                        if (amountleft == 0) {
                          e.remove();
                        }
 else {
                          if (item.getItemStack().getAmount() > amountleft) {
                            item.getItemStack().setAmount(amountleft);
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
 catch (            Exception e) {
              System.out.println("String_Node_Str");
              e.printStackTrace();
            }
          }
 else {
            StopDropTimer();
          }
        }
      }
    }
,0L,20L);
  }
}