Hey,
If you both are getting an issue with cloud syncing causing you to be unable to launch the game, can you please try the following:
1. Open Uplay as administrator, click the menu icon at the top left and go to settings.
2. Untick "Enable cloud save synchronization for supported games"
3. Make backup of savegames - default location C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\savegames
4. Launch game, play till the game makes an autosave or you manually save. If you could play for approximately 5-10 minutes.
5. Quit game, re-enable cloud saves and launch game again.
6. Select local save when prompted. Saves should be resynced.