Problem with autosave function?

Question

I get the following error with this code below this text.
Message=Cross-thread operation not valid: Control 'richTextBox1' accessed from a thread other than the thread it was created on.
Can someone help me?

 private void OnTimeEvent(object sender, System.Timers.ElapsedEventArgs e) 
            {
                if (saved == true)
                {
                    saved = false;
                    richTextBoxInfo.Invoke((MethodInvoker)(() => richTextBoxInfo.Text = richTextBoxInfo.Text));
                    File.WriteAllText(@"wininfo.txt", richTextBoxInfo.Text);
                    timerSave.Stop();
                    MessageBox.Show("Saved!");
                }
            }

Answer 1

Try changing two lines:

string text = null;
richTextBoxInfo.Invoke((MethodInvoker)(() => text = richTextBoxInfo.Text));
File.WriteAllText(@"wininfo.txt", text);

Also check if the saved variable is used correctly.