Problem with autosave function?

[kenne76]

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!");
                 }
             }