License activation problems When the installer cannot activate your license it says which kind of problem it met. Each kind has its own fix.
Is my license tied to a domain? Yes. A license is bound to the hostname of your installation. www.example.org and example.org count as the same hostname.
What happens if the license check cannot reach the license server? Your site keeps working. Normal requests check a signed copy of the license locally; a remote check runs on a seven-day schedule, and if one cannot be completed a grace period applies.