As of Dataplex version 1.3.0.1, a product key is no longer necessary to activate your Dataplex software. You still need to have a Dataplex-enabled SSD product, but the product key is no longer needed.
If you are having trouble getting older versions of Dataplex to recognize your product key, it is strongly recommended that you uninstall the older version of Dataplex, download Dataplex v1.3.0.1, and install the new version.