if anybody is still having a hard time getting far cry 4 to work heres what I did after 5 separate downloads and installation fails..using revo uninstaller I completely removed uplay and all registry files associated with it (back up your save folder).then restarted my pc in safe mode with networking and reinstalled uplay..rebooted my pc and downloaded far cry 4 again..installed and it worked fine and keeps working..seeing as ubi****e wont answer emails I phoned the tech line and a very helpful person advised me on which steps to take..i hope this is of use to anybody having issues..not quite sure why ubi****e didn't make this a sticky..