Look in "Discussions" about the update trouble of "infinite loop", best to download the whole patch 2.0 and use the activation key again and it works as it should but, thats uplay madness of "fixing" what should be already by the app, you got to fix it by yourself, but its great game and worth the trouble to get it running.

https://uk.gamesplanet.com/community/anno-2070-uplay-key--1451-1/discussions/80083-how-to-stop-the-infinite-reboot-loop