Bad License Key: BEGIN PGP SIGNED MESSAGE not found means that you have not selected a license key. A license key always starts with BEGIN PGP SIGNED MESSAGE and the text you are trying to paste does not. Please select & copy & paste your complete license key as shown in the How do I activate my license? manual:
Please select the entire text in the grey text area under License Key(includingBEGIN PGP SIGNED MESSAGE at the very top and includingEND PGP SIGNATURE at the very bottom). Your License Key is the entire text in the License Key text field and includes both human-readable and gibberish text sections.