After upgrading to PAN-OS 8.1, the Panorama
virtual appliance will check if a device management licenses has
been successfully installed. If a device management license has
not been successfully installed, or the number of firewalls managed
by the Panorama virtual appliance exceeds the device management
license limit, you have 180 days to install a valid device management
license. If no valid device management license has been installed,
the following alert appears each time you log in to the Panorama
web interface: