How to Fix Error 20 iTunes

Symptoms

Security software manufactured by companies other than Apple (“third party”) can prevent iTunes and other Apple applications from communicating with Apple servers or resources on your PC. Symptoms may include:

  • Unable to connect to, purchase, or download iTunes Store content
  • Unable to activate, backup, update or restore iOS device or iPods using iTunes
  • Unable to download iOS device or iPod software
  • Unable to sync content to iOS device or iPod
  • iOS device or iPod not seen in iTunes
  • Unable to connect to Home Sharing or Music Sharing in iTunes
  • Apple TV not seen in iTunes
  • Unable to launch iTunes
  • Unable to sync or stream content to Apple TV

These issues can often be resolved by updating, correctly configuring, or uninstalling security software.

Resolution:

1. Verify that the issue is a third-party security software issue.

There are some issues that may appear to be related to third-party security software but may be caused by other circumstances. Before making changes to your security software:

Note: For steps to identify if your security software is blocking a particular port, see the Advanced Steps under the Additional Information section of this article.

2. Update your security software

Security software companies regularly provide updates to their trusted site and application lists. If you have recently updated or installed new versions of Apple software, such as iTunes or Safari, updating your security software may resolve the issue. To update your security software, first determine what security software you have installed.

There are many means of determining what applications you have installed on your PC. 

  • Click the Start Menu (or button) and read through the list of programs.
  • Check the notification area (the lower-right corner of the task bar) for security applications.
  • Browse installed applications under Control Panel > Add/Remove.

Find what security software is installed and update it to the latest available version. This may be possible through the application itself but when in doubt contact the manufacturer for assistance. Use the following list to identify software you may have installed on your system and to locate available updates.

After updating your security software, run a virus scan.

List of third-party security applications

3. Configure your security software

After updating your security software, configure it correctly to allow iTunes to contact Apple. The steps used to properly configure the security software will vary, and to find the exact steps, visit the manufacturer’s support website or otherwise contact them for assistance.

Useful information for configuring your security software:

IMPORTANT: iTunes must be allowed to contact Apple using the following ports and servers:

  • port 80
  • port 443
  • phobos.apple.com, deimos3.apple.com, albert.apple.com, gs.apple.com, itunes.apple.com, ax.itunes.apple.com

For a more complete list of ports used by Apple products see “Well known” TCP and UDP ports used by Apple software products.

iTunes also contacts VeriSign servers during an iPhone restore and activation:

  • evintl-ocsp.verisign.com
  • evsecure-ocsp.verisign.com

For more information see Update and restore alert messages on iPhone and iPod touch

4. Temporarily disable or uninstall your security software

If the current available version of your security software is incompatible with iTunes, you can disable the security software and test if it is the source of the issue. It might also be necessary to temporarily uninstall security software after making sure you can reinstall it and note any required licenses. A temporary deinstallation might be required because parts of some security software remain active in the background though they appear to be deactivated.

To reduce any security risks that security software is designed to prevent, consider making sure all files needed to reinstall it are available and disconnect network connections before uninstalling security software. Should this not be possible, such as if a download without active security software is required, that required step should be the only process completed without security software. For assistance in checking your configuration, disabling, or uninstalling your security software, please contact the manufacturer.

Once disabled or uninstalled, perform only the steps required to verify your issue has been resolved. Complete whatever update, restore, syncing, back up, activation, or other task you were troubleshooting. Once that task is complete, install and configure compatible security software to ensure your PC is protected.