Plesk is inaccessible: Unable to connect to pipe \\.\pipe

Symptoms

• Plesk is inaccessible with the following error:

  ERROR: Exception: Unable to get administrator password: The system cannot find the file specified. (Error code 2) at Unable to connect to pipe \\.\pipe\
  

• In Windows Event Viewer, the following error appears in Plesk section:

  Unhandled exception
  
  E06D7363
  
  Execute file name: C:\Program Files (x86)\Parallels\Plesk\admin\bin\plesksrv.exe
  

• Plesk Management Service is being restarted endlessly

• Task manager shows that Parallels.MonitorSrv.exe process consumes a lot of memory

Cause

This is Plesk bug with ID #PPP-28421 . It was fixed in Plesk Onyx 17.5 MU#4.

Resolution

Upgrade to the latest available stable Plesk Onyx version.

As a workaround for Plesk Onyx 17.0, upload a patch to the server and extract it to %plesk_bin% directory.