A domain in Plesk intermittently shows error 403 or 404: incorrect Document Root is parsed by the webserver

Symptoms

• With disabled option Serve static files by nginx website(s) or javascript (.js) files (In the Browser console) intermittently show either of the following errors:

  403 Forbidden

  ---

  404 Not Found

• The document root for the website was recently changed at Plesk > Domains > example.com > Hosting Settings to another location, for example, to httpdocs/public

• The following error can be observed in the domain’s log file /var/www/vhosts/example.com/logs/error_log:

  AH01276: Cannot serve directory /var/www/vhosts/example.com/httpdocs/: No matching DirectoryIndex (index.html,index.cgi,index.pl,index.php,index.xhtml,index.htm,index.shtml) found, and server-generated directory index forbidden by Options directive

Cause

The webserver tries to parse the incorrect (old) document root due to stuck Apache processes.
This is Apache bug #63169

Resolution

1. Connect to the server via SSH;

2. Restart Apache service:

   • For Debian/Ubuntu:

     # systemctl restart apache2

   • For RHEL/CentOS:

     # systemctl restart httpd