The license file was created using the version 3.0 generator. To confirm, open the license file using notepad and the following will be seen:
License Generator="File" GeneratorVersion="3.0"
Archive Manager 5.3 does not support the newer version 3.0 licenses.
Please contact the licensing team and request a new key to be created using the license generator version 2.0.
The licensing team can be contacted at licensing@quest.com.