[SOLVED]Problems with sending ArrayList over network

Newbie & Debugging Questions
#1

Hello javagaming community.
I am working on a multiplayer game using kryonet. I am trying to send an arraylist over the network but everytime I send the it, the server crashes and there is no exception thrown.
How can I fix this bug? ??? ???

Sending the bullets over the network:



public void update(float delta)
{
//networkBullets and bullets are arraylists
if(networkBullets != bullets)
		{
  //send bullets over to the server
			PacketUpdateBullet packet = new PacketUpdateBullet();
			packet.bullet = bullets;
			network.client.sendUDP(packet);

			networkBullets = bullets;
		}
}

Adding to the bullets arraylist:


public void shoot() {

		if(bullets.size() == MAX_BULLETS) return;
		bullets.add(new Bullet(x, y, radians));
		Jukebox.play("shoot");
		Spaceoids.cam.project(new Vector3(x, y, 0));

	}

Thank you for your support.
EDIT: Thank you chrislo27, VaTTeRGeR, basil_ for helping me solving this problem