Unable to login to Plesk control panel: Unable to connect to pipe

Symptoms

• After logging into Plesk the following error is shown:

  PLESK_ERROR: Error message or request description : Unable to connect to pipe \\.\pipe\P_7da1332a-fe05-4176-91f2-4c4457fb71f0at (Con::ClientOverlappedPipe::create line 509)at get shared instance of PleskSrvClient(PleskSrvClient::getInstance line 327)at Unable to get administrator password: <Password has been wiped out for security reasons> line 205)

  Or:

  PLESK_ERROR: ERROR: Exception: Access is denied. (Error code 5) at Unable to connect to pipe \\.\pipe\P_36a625a6-260f-44af-b844-3beee654dbd6<br> at (Con::ClientOverlappedPipe::create line 503)<br> at get shared instance of PleskSrvClient(PleskSrvClient::getInstance line 337)<br> at Unable to get administrator password:(zif_get_admin_password line 206) (Helper.php:68)0: Helper.php:68get_admin_password()...AutoPrepend->run()9: auth.php:690

• Attempt to upgrade Plesk fails with the same error.

Cause

Plesk Management Service is stuck, not started or not available.

Resolution

1. Connect to the server via RDP.

2. Restart the Plesk Management Service via Plesk Services Monitor (Plesk icon in the tray menu):
   

3. If it is not restarting, kill the plesksrv.exe process in Task Manager and restart the service along with PopPass service:
   

4. Run %plesk_dir%admin\bin\reconfigurator.exe > Repair Plesk Installation > Plesk services: