I bought Farcry 4 and it installs fine into UPlay, however it wanted an update but while trying to update, it stays at 0B/s during downloading and doesn't complete.
I investigated the logs for uPlay which showed many "read time out" and "connection aborted" messages leading me to think it was a firewall issue however changing firewall options (and turning it off entirely) made no different. I also tried turning off all the other modules with no change such as disabling all options in the "Traffic Scan" and disabling "On access scanning" entirely.
I tried many different things like resetting my network stack, adjusting receive windows, and other TCP options using netsh to try to get it working and finally had partial success using a HTTP proxy, however, it was still unreliable. I then recorded the TCP packets using Wireshark which showed lost, out of order packets and duplicate ACKs that showed to me that something was interfering with the download.
Using the UPlay logs I was able to successfully download the file mentioned using Firefox, however UPlay still appeared to time out for some reason.
After much hair pulling I eventually I found this post:/index.php?showtopic=57257" rel=""> [escalated to testing team] Bitdefender Is Blocks Uplay From Ubisoft from 2015.
I tried as the user mentioned and uninstalled Bitdefender, and upon reboot UPlay had no issues doing the update and worked flawlessly.
I then reinstalled Bitdefender and UPlay cannot complete the update properly.
A workaround was provided in the 2015 post (which appears to disable/remove the HTTP scanning module), however, no permanent fix was released.
Please re-escalate this issue to the 2016 team as it appears it still exists.
Windows 10
BitDefender Internet Security 2016 - Build 20.0.28.1478