Hello @djdeath753 thank you for getting in touch with us about this error code.
To resolve this, could you please open your gamesettings.ini file in a text editor, then change the value "UseProxyAutoDiscovery" from 0 to 1 and then save this file. This was known to help some players on PC prevent the 4-0 error codes from occurring in-game.
If this does not prevent the error code from appearing, would you please make sure to follow all the steps in our connectivity troubleshooting guide, as this contains the most common steps for improving a player's connection to the game to the game's servers > https://ubi.li/YPwnl
Whilst we can not guarantee you will never see this error code again and disconnection, you shouldn't be experiencing it each game session.