Error while accessing Backup Manager: Cannot create python process

Symptoms

• Accessing Tools & Settings > Backup Manager results in error:
  

  PLESK_ERROR: Failed to parse response. Reason: XML error at line 1 column 1. Error message: Not well-formed (invalid token) Process output: Cannot create process: C:\PROGRA~2\PARALL~1\Plesk\Additional\Python\python.exe "C:\Program Files (x86)\Parallels\Plesk\admin\bin\PMMcli-runner.py" --get-dumps-list

  or:

  CONFIG_TEXT: Internal error: Failed to parse response. Reason: Failed to read data from stream Process output:
  Message Failed to parse response. Reason: Failed to read data from stream Process output:
  File PMMConnector.php
  Line 708
  Type PleskPMMResponseException

  or:

  CONFIG_TEXT: Internal error: Failed to parse response. Reason: Failed to read data from stream Process output:
  Message Failed to parse response. Reason: Failed to read data from stream Process output:
  File PMMConnector.php
  Line 839
  Type PleskPMMResponseException

• In %plesk_dir%\admin\logs\php_error.log there is a following message:
  

  CONFIG_TEXT: PleskPMMResponseException: Failed to parse response. Reason: Failed to read data from stream Process output:
  file: %plesk_dir%\admin\plib\backup\protocol\PMMConnector.php
  line: 708
  code: 0
  trace: #0 %plesk_dir%\admin\plib\backup\protocol\PMMConnector.php(299): PMMConnector->getResponse(Object(StreamXMLReader))

  or:

  CONFIG_TEXT: DEBUG [util_exec] [5936589127c4b] Starting: pmmcli --get-tasks-list, stdin:
  DEBUG [util_exec] [5936589127c4b] Finished in 0.0224s, Error code: TRUE, stdout: , stderr:
  ERR [1] PleskPMMResponseException: Failed to parse response. Reason: Failed to read data from stream Process output:
  file: C:\Parallels\Plesk\admin\plib\backup\protocol\PMMConnector.php
  line: 839
  code: 0

• Running PMMcli.exe binary in command line outputs an error:

  C:\> "%plesk_bin%\PMMcli.exe" --help
  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
  File "C:\\Program Files (x86)\Parallels\Plesk\admin\share\pmmcli\pmmcli.py", line 8, in <module>
  import libxml2
  ImportError: Bad magic number in C:\Program Files (x86)\Parallels\Plesk\admin\lib\python\libxml2\libxml2.pyc

  or

  C:\> "%plesk_bin%\PMMcli.exe" --help Traceback (most recent call last): File "C:\Parallels\Plesk\admin\bin\PMMcli-runner.py", line 13, in import pmmcli File "C:\Parallels\Plesk\admin\share\pmmcli\pmmcli.py", line 13, in from xml.parsers.expat import ExpatError ImportError: cannot import name ExpatError

  or

  C:\> plesk sbin pmmcli --get-tasks-list Backup
  Traceback (most recent call last):
    File "D:\Program Files (x86)\Parallels\Plesk\admin\bin\pmmcli-runner.py", line 14, in <module> import pmmcli
    File "D:\Program Files (x86)\Parallels\Plesk\admin\share\pmmcli\pmmcli.py", line 16, in <module>  import pmm_task
    File "D:\Program Files (x86)\Parallels\Plesk\admin\share\pmmcli\pmm_task.py", line 6, in <module> import osutil
    File "D:\Program Files (x86)\Parallels\Plesk\admin\lib\python\osutil.py", line 251, in <module>
      from win32file import CreateFile, LockFileEx, UnlockFileEx, CloseHandle
  ImportError: DLL load failed: The specified module could not be found.
  exit status 1

• While removing Reseller or Customer, the below error can appear:

  PLESK_ERROR: Some of the selected resellers were not removed.
  Failed to parse response. Reason: Failed to read data from stream Process output:

Cause

Corrupted Python installation.

Resolution

1. Login to the server via RDP.
2. Remove all *.pyc files from %plesk_dir%admin\lib\python folder.

If the issue persists, reinstall Python using the following steps:

1. Launch 'python.msi' installer:

   For Plesk 12.0 and lower
   Launch installer from C:\ParallelsInstaller\parallels\PANEL-WIN_<plesk_version>\thirdparty-msi-Windows-any-x86_64\plesk-python.msi folder.
   
   For Plesk 12.5 and higher
   Launch plesk-python.msi at 'C:\ParallelsInstaller\parallels\PANEL-WIN_<plesk_version>\dist-msi-Microsoft-2003-i386


   Note: If file 'python.msi' or 'plesk-python.msi' is absent, download it from the following site: http://autoinstall-win.plesk.com .

   Note: For Plesk 12.5 upgraded from previous version, python.msi should be taken from C:\ParallelsInstaller\parallels\PANEL-WIN_12.0.18\ hirdparty-msi-Windows-any-x86_64

2. Follow the installation wizard instructions, specify C:\Program Files (x86)\Parallels\Plesk\Additional\Python\ as installation path if required.

3. If the issue persists for the version 12.0 and lower, launch 'plesk-python.msi' from C:\ParallelsInstaller\parallels\PANEL-WIN_<plesk_version>\dist-msi-Microsoft-2003-i386 folder & reinstall Plesk Python.

Additional Information

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

Unable to access Backup Manager after Update: Failed to parse response. Reason: Failed to read data from stream Process output