Hi @allaccessfa,
Sorry to hear you are hitting difficulties here.
That particular message displays independently of whether or not your license key has been activated – but you can certainly clear existing keys by deleting them on the original site and also here on the accounts management page, then simply re-enter it on your new site.
Remember also that you can update plugins like Events Calendar PRO manually if you need to by grabbing a copy from our downloads page and uploading them over the old copy.
Do either of those options work for you here?