ObjectInputStream causing crash

Question

my computer seems to crash when I have I try to send an object from server, line 27 tries to receive the object, I think I got an invalid type code:0 once but usually just crashes so I have to restart

          new Thread(){
          public void run(){
              boolean sent = false;
              boolean threadStarted = false;
              while(true){
                  if(game.changedTurns){
                     System.out.println(game.changedTurns);
                     if(!sent){
                        try{
                            System.out.println("attempt to send from player");
                            out.writeObject(game.getSquareColors());
                            System.out.println("sent");
                            sent = true;
                            //Thread.sleep(500);
                            sent = false;
                            }
                            catch(Exception ex){
                                System.out.println("player1 " +ex.getMessage());  
                            }
                          }
                      }if(!threadStarted)                       
                          threadStarted = true;
                          new Thread(){
                          public void run(){
                              while(true){
                                  try{
                                      Object ob = in.readObject();  // line 27  

                                      System.out.println("Player received");
                                  }
                                  catch(Exception e){
                                      System.out.println("player2 "+e.getMessage());  
                                  }
                              }
                          }
                      }.start();
                  }
              }
          }.start();
      }

an object is sent to the server from another client, server recieves and tries to send object at line 16:

 class Opponent implements Runnable{    
    ObjectInputStream in2;
    ObjectOutputStream out;
    Opponent(ObjectInputStream in2, ObjectOutputStream out){
        this.in2 = in2;                                                             //from opponent to player
        this.out = out;
    }
    public void run(){                                  
        while(true){
            try{
                System.out.println("from opponent to server waiting");
                Object o2 = in2.readObject();
                if(o2 instanceof Color[]){
                    System.out.println("fee");
                    out.writeObject(o2);                  //line 16
                    out.flush();
                }
            }
            catch(Exception e){
                System.out.println("S2 " +e.getMessage());
            }
        }
    }
}

}

Answer 1

Object I/O streams sends some headers to each other before starting to transmit object so my recommendation is at end 1 create first the output stream and at the end 2 create the input stream then at end 1 create the input stream and at end 2 create output stream or vice versa
Computer crashing seems very odd result this usual Object I/O streams miss use