C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace AplikacioniStudentet
{
    public partial class FormaStudentet : Form
    {
        public FormaStudentet()
        {
            InitializeComponent();
           
        }

        private void Form1_Load(object sender, EventArgs e)
      
        {

        }

        private void textBoxID_TextChanged(object sender, EventArgs e)
        {
            string pathi = "Studentet.txt";
            using (FileStream fs = new FileStream(pathi, FileMode.Create))
            {
                using (StreamWriter sw = new StreamWriter(fs))
                {
                    foreach (string line in textBoxID.Lines)
                        sw.Write(line + sw.NewLine);
                    sw.Close();
                }
            }
            
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string pathi = "Studentet.txt";
            using (FileStream fs = new FileStream(pathi, FileMode.Create))
            {
                using (StreamWriter sw = new StreamWriter(fs))
                {
                    sw.WriteLine(textBoxID.Text + " " + textBoxEmri.Text + " " + textBoxMbiemri.Text + " ");
                    sw.Flush();
                    sw.Close();
                }
            }
           
            /*TextWriter tw = new StreamWriter (pathi, true);
            tw.ID = ID;
            tw.emri = emri;
            tw.mbiemri = mbiemri;


            tw.Close();*/
            
        }

        private void textBoxEmri_TextChanged(object sender, EventArgs e)
        {
            string pathi = "Studentet.txt";
            using (FileStream fs = new FileStream(pathi, FileMode.Create))
            {
                using (StreamWriter sw = new StreamWriter(fs))
                {
                    foreach (string line in textBoxEmri.Lines)
                        sw.Write(line + sw.NewLine);
                    sw.Close();
                }
            }
        }

        private void textBoxMbiemri_TextChanged(object sender, EventArgs e)
        {
            string pathi = "Studentet.txt";
            using (FileStream fs = new FileStream(pathi, FileMode.Create))
            {
                using (StreamWriter sw = new StreamWriter(fs))
                {
                    foreach (string line in textBoxMbiemri.Lines)
                        sw.Write(line + sw.NewLine);
                    sw.Close();
                }
            }
        }

        private void listBoxStudentat_SelectedIndexChanged(object sender, EventArgs e)
        {
            ListBox lb = new ListBox();
            System.IO.StreamReader sr = new System.IO.StreamReader("Studentet.txt");

            while (!sr.EndOfStream)
            {
                lb.Items.Add(sr.ReadLine());
            }

            sr.Close();
           
        }
    }
}

The semaphore timeout period has expired.

public static void Open_ActivePortWeWillUse(String Drone_StringNameFromUser)
    {
        SerialPort TempSerialPort = new SerialPort(Drone_StringNameFromUser, (int) SerialPortSpeed);

        ThePorts.ActivePort1 = TempSerialPort;

        ThePorts.ActivePort1.DataBits = 8;
        ThePorts.ActivePort1.Parity = Parity.None;
        ThePorts.ActivePort1.StopBits = StopBits.One;

        ThePorts.ActivePort1.DataReceived += new SerialDataReceivedEventHandler(OurBackGroundSerialPortReceiver);

        ThePorts.ActivePort1.Open();  // The "Sometimes" Error occurs here
    }

public partial class Login : Form
    {
        public Login()
        {
            InitializeComponent();
        }

        private void Button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void Button1_Click(object sender, EventArgs e)
        {
            if ((textBox1.Text == "puppy") && (textBox2.Text == "password"))
            {
                MessageBox.Show("Welcome Puppy", "Success",
                MessageBoxButtons.OK, MessageBoxIcon.Information);

                this.Dispose();
            }

            else
            {
                MessageBox.Show("Wrong username or password","Invalid Input",
                    MessageBoxButtons.OK,MessageBoxIcon.Error);
            }