Plesk is inaccessible: Unable to get PSADb administrator password

Symptoms

• Plesk is inaccessible with the below error in browser:

  ERROR: Exception: Unable to get PSADb administrator password: The system cannot find the file specified. (Error code 2) at Unable to connect to pipe .pipeP_7da1332a-fe05-4176-91f2-4c4457fb71f0at<br> at (Con::ClientOverlappedPipe::create line 503)<br> at get shared instance of PleskSrvClient(PleskSrvClient::getinstance line 348)<br> at (zif_get_psadb_admin_password line 251)

  Additionally, an exception has occurred while trying to report this error: Zend_Exception
  No entry is registered for key &#039:dbAdapter' (Helper.php:68)

• The plesk login command returns the following error:

  C:> The system cannot find the file specified. (Error code 2) at Unable to connect to pipe .pipeP_949c3a9a-99ed-4320-b349-b9e25ce62cdc
  at (Con::ClientOverlappedPipe::create line 518)
  at get shared instance of PleskSrvClient(PleskSrvClient::getInstance line 364)
  at Unable to execute CU(wmain line 85)exit status 1

• Plesk Management Service is shown as stopped and cannot be started with the following error:

  The service cannot accept control messages at this time. (Error code 1061) at ControlService 'plesksrv' with code 1
  at (service::controlServie line 508)
  at startService(plesksrv)(service::startService line 274)

Cause

The plesksrv.exe process is hung.

Resolution

Warning: If the process is not shown in Task Manager, kill the process with Process Explorer Sys utility: https://docs.microsoft.com/en-us/sysinternals/downloads/process-explorer

1. Connect to the Plesk server via RDP.

2. Start Windows Task Manager and end the plesksrv.exe process.

3. Start Plesk Management Service from Plesk Services Monitor or Windows Services.