If you try running Anno 2070 without Uplay installed in the bottle, then Anno 2070 will try and install Uplay. The version of Uplay that it tries to install is so old that it cannot update itself to a working version.
Just use the CrossOver Configure // Install Software... menu item to install Uplay and make sure that in the Select Bottle tab that you select your Anno 2070 bottle. This version of Uplay will update itself to a working version.
If you do let Anno 2070 try and install Uplay, then you will need to uninstall the broken version of Uplay. Use the Run Command... item on the CrossOver Bottle menu and then browse for the uninstall.exe command in your bottle. It will be in a folder called Program Files\Ubisoft\Ubisoft Game Launcher.
