Java.IO.StreamCorruptedException: 無効なストリーム ヘッダー

package delftstack;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.ClassNotFoundException;
import java.net.ServerSocket;
import java.net.Socket;

public class Example {
  private static ServerSocket Server_Socket;
  private static int Port_Number = 5000;

  public static void main(String args[]) throws IOException, ClassNotFoundException {
    Server_Socket = new ServerSocket(Port_Number);
    while (true) {
      System.out.println("Waiting for client request");
      // create socket and then wait for client connection
      Socket DemoSocket = Server_Socket.accept();
      // read from socket to the ObjectInputStream object
      ObjectInputStream Object_Input_Stream = new ObjectInputStream(DemoSocket.getInputStream());
      // convert the ObjectInputStream to the String
      String DemoMessage = (String) Object_Input_Stream.readObject();
      System.out.println("The Received Message is: " + DemoMessage);
      // ObjectOutputStream object
      ObjectOutputStream Object_Output_Stream =
          new ObjectOutputStream(DemoSocket.getOutputStream());
      // write object to the Socket
      Object_Output_Stream.writeObject("Hello Client " + DemoMessage);
      // close
      Object_Input_Stream.close();
      Object_Output_Stream.close();
      DemoSocket.close();
      // terminate the server on exit from the client
      if (DemoMessage.equalsIgnoreCase("exit"))
        break;
    }
    System.out.println("Shut down Socket server!!");
    // close the ServerSocket
    Server_Socket.close();
  }
}

Exception in thread "main" java.io.StreamCorruptedException: invalid stream header: 54657374
    at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:803)
    at java.io.ObjectInputStream.<init>(ObjectInputStream.java:298)
    at Example.main(SocketServerExample.java:29)