I am getting the following error when compiling a **Java** class in **BlueJ**.

```
AuctionManager.java uses unchecked or unsafe operations.

```

This error is only displayed when the following deserialization code is in one of my functions:

```
try {
  ObjectInputStream in = new ObjectInputStream(new FileInputStream(Filename));
  ArrayList<AuctionItem> AuctionList = (ArrayList<AuctionItem>) in.readObject();
  in.close();
}
catch (Exception e) {
  e.printStackTrace();
}

```

Can I please have some information as to why this error is being displayed, and some help to use the deserialization code without the error.