Crashing onAction of a button - javafx

Question

I'm writing a java data transmission program with javafx. Everything runs fine, but when i hit the "send"button in Scene 2 on my program (and the receive button in Scene 3) it crashes my program without any error appearing.
This is my controller class for my Scene 2.
The problem lies probably in function "send()". This is is the code for creating port and transfer file.
public class ControllerSc2 {
#FXML
public Button browsebut,sendbut,backbut;
#FXML
public TextField Path;
#FXML
public TextArea info;
public Socket socket;
public String path,name;
public void browseButton() {
FileChooser fc = new FileChooser();
File sf = fc.showOpenDialog(null);
if(sf != null){
Path.setText(path = sf.getAbsolutePath());
info.setText("Name: "+ (name = sf.getName()) +"\n" + "Size: "+ sf.length() +"Bytes \n" +"From Path: "+ sf.getAbsolutePath() +"\n");
}
else{
Path.setPromptText("please choose something!");
info.setPromptText("No File was chosen!");
}
}
public void back(){
Main.ShowScene1();
}
//NOTE!!!!!!: critical problem in send function
public void send() throws IOException{
ServerSocket serverSocket = new ServerSocket(5000);//this is the code making the program listen to connection from a port
info.setText("Waiting for connection");
socket = serverSocket.accept();//waiting connection
info.setText("Connected....");
/*DataOutputStream dout=new DataOutputStream(socket.getOutputStream());//
dout.writeUTF(name);//transfer name */
//File transferFile = new File(path);
File transferFile = new File("C:\\Users\\longt\\IdeaProjects\\a.docx");
byte[] bytearray = new byte[(int) transferFile.length()];
FileInputStream fin = new FileInputStream(transferFile);
BufferedInputStream bin = new BufferedInputStream(fin);
bin.read(bytearray, 0, bytearray.length);
OutputStream os = socket.getOutputStream();
System.out.println("Sending Files...");
os.write(bytearray, 0, bytearray.length);
os.flush();
socket.close();
System.out.println("File transfer complete");
}
}
`