Ensure you have administrator rights when running the activation. You may also need to temporarily disable your firewall or antivirus to allow the local loopback communication.
For official support, you can visit the Artlantis Support Portal to find specific guides for your version. 127001 activationabventcom
For network licenses, confirm that the Artlantis KeyServer service is actually running on the host machine. Ensure you have administrator rights when running the