Plesk on Windows interface is not accessible: 500 Internal Server error

Symptoms

• Plesk is not accessible:

  PLESK_INFO: 500 Internal Server error

• No errors are logged in php_error.log with debug mode enabled.

• After temporary renaming web.config file inside %plesk_dir%admin\htdocs, Plesk starts to load with this error message locally on the server:

  PLESK_INFO: HTTP Error 500.21 - Internal Server Error
  Handler "PleskEngine-FastCGI-php" has a bad module "FastCgiModule" in its module list

Cause

FastCgiModule is absent among Modules in the server-wide IIS settings or not installed

Resolution

1. Connec to the server via RDP.

2. Start IIS Manager and go to IIS > SERVERNAME > Modules.

3. On the Actions pane, click Configure Native Modules and select FastCgiModule.

Note: If it is absent in the list, click Register and specify the following values:

• Name: FastCgiModule
• Path: %windir%\System32\inetsrv\iisfcgi.dll

4. Click Ok