Backup manager cannot be opened: Failed to parse response. Reason: Failed to read data from stream

Symptoms

• The Backup Manager at Plesk > Tools & Settings cannot be opened with the following error message:

  PLESK_ERROR: PleskPMMResponseException: Failed to parse response.
  Reason: Failed to read data from stream
  Process output: file: C:\Program Files (x86)\Parallels\Plesk\admin\plib\backup\protocol\PMMConnector.php line: 840

• The command below fails with an error:

  C:\> plesk sbin pmmcli --get-tasks-list Backup
  
  ImportError: No module named libxml2

  C:\> C:\Program Files (x86)\Parallels\Plesk\admin\bin\PMMcli.exe --help
  Traceback (most recent call last):
  File "C:\Program Files (x86)\Parallels\Plesk\admin\bin\PMMcli-runner.py", line 14, in <module>
  import pmmcli
  ImportError: No module named pmmcli 

• The PYTHONHOME variable has a path different from %plesk_dir%Python:

  C:\> set | findstr PYTHONHOME
  
  PYTHONHOME= C:\Python

• plesk_dir variable path differs from the following:

  C:\> set | findstr plesk_dir
  plesk_dir=C:\Program Files (x86)\Plesk\

Cause

The PYTHONHOME or plesk_dir variables are set incorrectly.

Resolution

1. Connect to the Plesk server via RDP.

2. Start Control Panel at Windows Start > All Programs.

3. In Control Panel click System > Advanced system setting, > Environment Variables....

4. In the System variables windows double-click the PYTHONHOME variable and change the Variable value to %plesk_dir%Python.

   

5. Click OK.

The same steps as above can be applied to update %plesk_dir% variable.