Drupal 7 update - An AJAX HTTP request terminated abnormally error

If you run into an “AJAX HTTP request terminated abnormally error” when updating a Drupal 7 website, it may be because your .htaccess file does a redirect to your www.domain.com and the base_url in your settings.php file refers to domain.com, or vice-versa. I ran into this Drupal/AJAX problem yesterday, and found the solution here on drupal.org.