When trying to activate the license, the message "License invalid" appears. In most cases, this message appears when a license key for a domain is blocked.
To fix the problem, log in to Borlabs Service and click on Licenses on the left. Now click on the gear icon next to your license. This will take you to the license details.
Click the Blocked Domains tab at the top. There you can remove the corresponding domain from the list by clicking the remove icon.