Unable to install Plesk via Web Installer: unable to parse private key: ssh: no key found

Symptoms

• Unable to start Plesk installation at Plesk Web Installer  > Install Automatically on a Server. The following error is shown:

  Cannot connect to ssh host 203.0.113.2: unable to parse private key: ssh: no key found

  ---

  Private SSH key is invalid

• The SSH private key option was chosen and a .PPK file was specified.

Cause

Incorrect SSH file: A .PPK file can only be launched and used by PuTTY.

Resolution

Convert the .PPK file to the supported one (.PEM).