Cross-thread operation not valid in Debug mode, but in Release mode all is okay

Question

Why I get an exception: "InvalidOperationException: Cross-thread operation not valid: Control lblText accessed from a thread other than the thread it was created on" :when running application in debug mode?:

namespace testFormApp
{
    public partial class Form1 : Form
    {
        public Form1() => InitializeComponent();

        private void Form1_Load(object sender, EventArgs e)
        {
            lblText.Click += (send, arg) => Need = false;
        }

        bool Need = true;

        private async void ButtonStart_Click(object sender, EventArgs e)
        {
            await Task.Run(async() =>
            {
                lblText.Text = "";
                while(Need)
                {
                    lblText.Text += ". ";
                    await Task.Delay(1000);
                }
            });
        }
    }
}

But same code in Release mode working without any problem. Why I'm getting this exception?

Answer 1

Checkout Hans Passant's answer on this question, Why is cross thread operation exception not thrown while running exe in bin\Debug he is saying cross-thread error checking is only enabled when a debugger is attached, also you can disable cross-thread errors check manually

Control.CheckForIllegalCrossThreadCalls = false;