If you want to manage and configure 3CX Phone System on Windows 2008 server operating systems, you will have to disable IE ESC on the server.

  1. Go to Start and click on “Server Manager”.
  2. Click on “Configure IE ESC” located on the right-hand section of the window.
  3. The Internet Enhanced Security Settings page will be displayed. Disable necessary options. IE ESC is now disabled.
    Internet Explorer Enhanced Security