As of late 2022, Ubisoft decommissioned certain online services for older titles, but Anno 2070 received an update to ensure the game remains playable and that players can still use their DLCs and online features. Always ensure your game client is up to date via the Ubisoft Help portal to avoid activation errors.
Even if you possess a high pain tolerance for pop-ups and malware risks, "Anno 2070" presents a specific technical hurdle that renders most key lists useless: Solidshield Tages DRM. Anno 2070 Serial Number List