There are a couple reasons why you may be getting an "Another instance of the viewer is already running" message. Follow these troubleshooting tips.

Your browser may be blocking the Viewer from launching.

  1. Open your default browser from your client computer.
  2. Log in to your GoToMyPC account.
  3. There will be a Pop-up Blocked warning icon by the browser address bar. Click on the warning icon and select the "Always allow for this site" checkbox.
  4. Reconnect to your host computer.

First connection may still be running.

  1. Check to see if there is a GoToMyPC session already running in the background.
  2. Force quit the app.
  3. Reconnect to your host computer.