Switching from one form to another doesn't work?

Question

C++ / C#

Greetings. Visual Studio cannot find Windows Form 2.
Tried everything, doesn't work.
I have 2 forms Form1 Form2

I decided to put a transition button from the first form to the second, it does not work.

private void button1_Click(object sender, EventArgs e)
        {
            Form2 newForm = new Form2();
            newForm.Show();
        }

I decided to launch the application immediately from the second form, it also does not work.

static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form2());
        }

Answer 1

The point was that everywhere the former names of the forms in the code had to be replaced with new ones.
Thanks to all.