Unable to install Plesk via get.plesk.com: plesk: command not found, failed to run: Process exited with status 127

Symptoms

Plesk installation via get.plesk.com fails with the following error:

CONFIG_TEXT: ERROR: The certificate of 'autoinstall.plesk.com' is not trusted.
ERROR: The certificate of 'autoinstall.plesk.com' hasn't got a known issuer.
Host: 203.0.113.2, command: bash - completed
Host: 203.0.113.2, command: bash -
bash: line 1: plesk: command not found
failed to run: Process exited with status 127

Cause

ca-certificates package is missing on the server.

To improve this functionality a request with the ID #WI-388 has been created. It is planned to be fixed in one of the future product updates.

Resolution

1. Connect to the server via SSH;

2. Install the ca-certificates package:

   # apt-get install ca-certificates

3. Run the Plesk installation at get.plesk.com again.