If you want the full power of ScanXL Pro safely, you can purchase a license key from or ScanTool.net , their authorized distributor. The license is permanent without time limits and can be added via the software's "Help -> License Manager" menu.
If a specific software version is discontinued or lacks updates for modern vehicle communication networks (such as CAN FD or DoIP), plan a migration path to modern, actively supported diagnostic platforms. scanxl pro 3.5.1 patch