Resolve Uplay connection issue.
In order to resolve the connection issue in Uplay, try power cycling your router. To do so follow the following steps below:
1. First turn it off, unplug it and wait a minute.
2. Then plug it and turn it on.
Additionally, try emptying the cache of Uplay PC as per following FAQ [Emptying the cache of Uplay] and make sure that Uplay isn't blocked by any Firewall or Antivirus software that you're using.