Apache service fails to start after Plesk or Sitebuilder update via control panel Updater.

Check PHP version and list of enabled modules from root shell, normally these commands should show an output:

# php -v
# php -m

In case of a problem no output is generated or segmentation fault happens.

CAUSE:

PHP IonCube loader extension is included several times or not in proper order.

RESOLUTION:

Find all IonCube loader entries in PHP configuration .ini files with command:

# grep -iR ioncube /etc/php*

Make sure that:
1) only one IonCube loader is included,
2) it corresponds with your PHP version, you can comment out all IonCube
entries and check PHP version with `php -v`.
3) it is included before all other Zend extensions.