To test your extension in real-life conditions, install it to Plesk by logging in to Plesk as the administrator and adding the extension on the Server Management > Extensions page. Below you will find Plesk configuration parameters that help you easily debug your extensions. Be sure to comment the parameters (by adding the leading ; symbol) after you complete testing and decide to use Plesk in production.

How to Improve the Verbosity of Debug Information

If your extension uses the Plesk GUI and it exits with an error or an exception, you should see the PHP stack trace. If you do not see it, and, say, see only a blank screen, try to improve the verbosity level of the debug output by adding the following lines to the panel.ini file:


Then, turn on PHP error reporting in php.ini. The file path is:

  • (Linux) /usr/local/psa/admin/conf/php.ini
  • (Windows) %plesk_dir%admin\conf\php.ini

Open the file and edit the display_errors and error_reporting settings:

display_errors = On
error_reporting = E_ALL & ~E_STRICT & ~E_DEPRECATED

After that, restart the Plesk web server.

How to Prevent Inconsistency Between Code and Results

If you are testing an extension on Linux, you may run across the problem with inconsistency between your code and expected result. The inconsistency happens because Plesk content is cached, so the cache must expire before you see the update. To mitigate this problem, turn the Plesk cache off. This is also triggered in php.ini by the following line:

apc.enabled = 0

The change will take effect after you restart the web server which handles requests to the Plesk GUI. The restart command is as follows:

/etc/init.d/sw-cp-server restart