Drupal errors

Drupal Downloading updates - An AJAX HTTP Error occurred

Error:

An AJAX HTTP error occurred. HTTP Result Code: 200 Debugging information follows. Path: /batch?render=overlay&id=213&op=do StatusText: parsererror ResponseText: Fatal error: require_once() [function.require]: Failed opening required '/home/<site>/public_html/modules/system/system.tar.inc' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/<site>/public_html/includes/bootstrap.inc on line 3119

Detectie:

Geconstrateerd na upgrade van Drupal core van 7.22 naar 7.23

Oplossing: