Imunify360 activation fails in Plesk: Servers limit exceeded for key

Symptom

• Imunify360 extension cannot be activated with a license purchased from Plesk.

• The following errors are shown when accessing the Imunify360 extension:

  PLESK_ERROR: Servers limit exceeded for key <KeyNumber>

  CONFIG_TEXT: No valid license was found for this Imunify360 installation. Please upgrade your license to continue using all benefits of the Imunify360.

• The following warning is shown while attempting to install extension manually via command line:
  

  CONFIG_TEXT: WARNING: License is invalid for current server
  Register by IP...
  WARNING: {"message":"Servers limit exceeded for key IY1ghpLItqZE8RQbV","type":"validation","success":false,"data":null}
  Registration was not successful.

Cause

Imunify360 license can be used on one installation at a time.

The error may appear due to one of the following reasons:

• More than one Imunify360 is activated with the Imunify360 license

• Imunify360 has been reinstalled on the same Plesk server, thus the same server to be registered twice

• Imunify360 was installed on the newly migrated server with the old server's IP address

Resolution

If the old server where Imunify360 is activated with the mentioned <KeyNumber> is still online, run the following command to unregister Imunify360:

# imunify360-agent unregister

If the old server is offline, contact CloudLinux Support for further assistance.