Unable to install a valid Plesk license key on the server with wrong date: The license key is invalid

Symptoms

• When installing a valid Plesk license, the following error message appears in Plesk:

  PLESK_ERROR: Error: The license key is invalid. In order to use Plesk, you need to obtain and install a new valid license key.
  Your license key has expired. To continue using your Plesk, you must purchase a non-expiring commercial license key.

• When retrieving or installing a Plesk license key at Plesk > License Management, the following error appears in Plesk:

  PLESK_ERROR: Error: Updated license key is not valid.

• When running the "date" command in a command-line interface, it shows incorrect date:

  # date

Cause

Wrong date is set on the server.

Resolution

1. Connect to the Plesk server via SSH.

2. Set the correct time using the command "date --set=". Here is an example:

   # date --set="23 April 2018 10:30:00"
   Mon Apr 23 10:30:00 CEST 2018

Additional Information

• Unable to install a Plesk license: The license key is invalid. Different license is shown in License Info