If you upgrade from 6.x to 7.x, the software may honor the old key until it expires, but it will display a notification that licensing has changed until the new 7.x file is applied. Troubleshooting and Best Practices Applying an offline license to RealVNC Connect
"C:\Program Files\RealVNC\VNC Server\vnclicense.exe" -add OFFLINELICENSE sudo /Library/vnc/vnclicense -add OFFLINELICENSE Linux sudo vnclicense -add OFFLINELICENSE Source: RealVNC Help Center Method B: Desktop User Interface vnc offline license file