The game returns to the menu when attempting to log in to UBI.com.

In order to play on Ubi.com, you need to install the latest patches 1.5 for the original version and 2.1 for the Hammers of Fate expansion. Without these updates, you will not be able to play on the official server. Your options are to install the latest patches or find like-minded players and play version 1.3 with them using Hamachi.