Plesk shows 500 Internal Server Error: The FastCGI process exited unexpectedly

Symptoms

It it not possible to login Plesk after upgrade: "HTTP Error 500.0 - Internal Server Error"

HTTP Error 500.0 - Internal Server Error
C:\\Program Files\\Parallels\\Plesk\\Additional\\PleskPHP54\\php-cgi.exe - The FastCGI process exited unexpectedly


Detailed Error Information:
Module     FastCgiModule
Notification       ExecuteRequestHandler
Handler    PleskEngine-FastCGI-php
Error Code     0xffffffff
Requested URL      https://localhost:8443/index.php
Physical Path      C:\\Program Files (x86)\\Parallels\\Plesk\\admin\\htdocs\\index.php

Cause

The root cause of the issue is that PHP package for Plesk is not upgraded.

Resolution

1. Download from autoinstall-win.plesk.com and unpack plesk-engine.msi , plesk-service-node-utilities.msi packages as follows:

   msiexec /a path_to_package\\plesk-engine.msi TARGETDIR=C:\temp\\ /qn
   msiexec /a path_to_package\\plesk-service-node-utilities.msi TARGETDIR=C:\temp\\ /qn
   

2. Create a backup of %plesk_bin% directory.

3. Replace not upgraded binaries with unpacked ones in %plesk_bin% directory.

   cd %plesk_bin%
   copy "C:\temp\\Program Files\\Parallels\\Plesk\\admin\\bin\\php.exe"
   copy "C:\temp\\Program Files\\Parallels\\Plesk\\admin\\bin\\php.dll"
   copy "C:\temp\\Program Files\\Parallels\\Plesk\\admin\\bin\\php-cgi.exe"
   copy "C:\temp\\Program Files\\Parallels\\Plesk\\admin\\bin\\phpcfg.exe"
   

4. Restart Plesk Management Service.