Plesk websites show Error 503 after Plesk upgrade: The Module DLL C:\Windows\system32\inetsrv\rewrite.dll failed to load

Symptoms

• Websites are not available after upgrading Plesk. The following error is shown:

  CONFIG_TEXT:  HTTP Error 503. The service is unavailable

• Events with ID 2280 can be found at Windows > Start > Event Viewer > Windows Logs > Application:

  CONFIG_TEXT: The Module DLL C:\Windows\system32\inetsrv\rewrite.dll failed to load. The data is the error.

  

  ---

  CONFIG_TEXT: Could not load type '%SystemRoot%\system32\inetsrv\rewrite.dll'.

Cause

%SytemRoot%\system32\inetsrv\rewrite.dll does not exist on the filesystem or it's corrupted. 

Resolution

1. Connect to the server via RDP;

2. Make sure that the rewrite.dll file exists in the folder %SystemRoot%\System32\inetsrv:

   • If the rewrite.dll doesn't exist, download the correct URL Rewrite Module version and install it at www.iis.net/urlrewrite 
   • If it exists, rename or remove %SystemRoot%\System32\inetsrv\rewrite.dll file and reinstall the package, which can be downloaded from www.iis.net/urlrewrite 

3. Open CMD as administrator;

4. Continue Plesk upgrade:

   C:\> plesk installer update