https://support.managed.com/kb/a1937/how-to-enable-php-error-logging-in-plesk-11.aspx


How to Enable PHP Error Logging in Plesk 11

This is for Plesk 11 only and will place a php.log.resources file in the httpdocs folder that will contain the PHP error log.  If you have a dedicated server, you can perform this yourself. If you have a shared account it will need to be done by a support technician.

 

  1. Log in to your Plesk Control Panel as an Admin.
  2. On the Domains tab section click on [domainname.com] .
  3. Click on the Websites & Domains tab.
  4. Expand Show Advanced Operations.
  5. Click on Website Scripting and Security.
  6. Click on the PHP Settings tab.
  7. Scroll down, at the very bottom, under Additional directives, paste the following into the Additional Configuration Directives field.
error_log = "{DOCROOT}\php.log.resources"

    8. Click OK.