Ubuntu 12.04 with apache 2.4 is installed or OS is being upgrading to Ubuntu 14.04 with apache 2.4
Domains reconfiguration fails with the following error:
ERR [panel] Apache config (14530640570.65770600) generation failed: Template_Exception: Can not restart web server: file: /opt/psa/admin/plib/Service/Driver/Web/Server/Apache.php line: 110 code: 0 DEBUG [util_exec] [569bfffb2195c] Starting: send-error-report /opt/psa/admin/bin/send-error-report From the `/var/log/plesk/panel.log`: DEBUG [util_exec] [45f53d4fd8587abc1e746ad36b388503] Starting: apache_control_adapter --restart --restart-interval 0 --http-port 80 --https-port 443 ERR [util_exec] proc_close() failed ['/opt/psa/admin/bin/apache_control_adapter' '--restart' '--restart-interval' '0' '--http-port' '80' '--https-port' '443'] with exit code  According to Apache logs the service is actually restarted successfully. As a result websites show Plesk default page.
apache_control_adapter utility monitors a wrong pid-file. This issue has been considered as software issue #PPPM-3904 and will be fixed in future Plesk updates.
Change apache PID file location in
/etc/apache2/envvarsto make utility
# grep -i pid /etc/apache2/envvars export APACHE_PID_FILE=/var/run/apache2.pid
- Restart apache.
Note: This error may appear on Plesk upgrade to 12.5 or OS dist-upgrade.