Some time after login into Plesk Control Panel if shows following error:
Server Error in '/' Application. This type of page is not served. Description: The type of page you have requested is not served because it has been explicitly forbidden. The extension '.php' may be incorrect. Please review the URL below and make sure that it is spelled correctly. Requested Url: /index.php
The problem occurs when Plesk panel site is not properly configured IIS. To configure it again you will have to re-create the Plesk website in IIS by switching Plesk database provider to apache and then back to IIS. Following are the steps to re-create the Plesk website in IIS
1) Change the Plesk Web server fom IIS to Apache. This can be done using following command
C:\Parallels\Plesk\admin\bin>reconfigurator --switch-plesk-web-server --new-provider=apache
2) Run Plesk re-configurator to re-configure everything and wait till it finishes.
3) Switch the Plesk Web server back to IIS from Apache
C:\Parallels\Plesk\admin\bin>reconfigurator --switch-plesk-web-server --new-provider=iis
4) Run Plesk Re-configurator again.