About avast free license invalid appeared on the next day when the computer is powered on without connected to the network.
Found the following situation:
1.Click Set-> Contract->Registration.Different versions connect to different ip addresses.
avast free antivirus ver 17.7.3660, avastui.exe will connect to my computer dns server address,and 203.208.43.94;203.208.51.94;203.208.39.254(Beijing China),can register successfully.
But when it came time to update the virus database,It will no longer connect to the above address and dns，
Start connecting only 119.81.94.2（Singapore），119.81.94.3， 119.81.142.202，119.81.142.203（Hong Kong）
Here, Unable to connect successfully. Need my Internet connection service provider vpn.
avast free antivirus ver 17.9.2322,avastui.exe only connect to the following ip:119.81.94.2（Singapore），119.81.94.3， 119.81.142.202，119.81.142.203（Hong Kong）.The same can not be registered successfully.Need vpn.
problem：why the new version of the software, in the case of Chinese servers can be directly connected, but to connect overseas servers？ Resulting in the software can not be authorized.
2.Can not connect to the registration server ip after the installation is complete,and upgraded the virus database。
The next day, the computer powered on, in the absence of connection to the Internet, the software showed license invalid. Did not determine whether the current connection to the network.
3.After the software fails, using VPN activation, can not be directly displayed has been activated successfully, the need to restart the computer to normal.