Same Problem here. 21 September (or 22 ? it's 23:59 right now) and the same problem has happened to me.
I'm directly connected to the modem so open some ports on the router won't help.
I have had a similar problem with AC:BF for the last few days. UPlay says i'm connected and can play, but in the game itself several of the online windows are greyed out, although I never gete a message about being offline unless I try to goto my fleet. I get a "Sorry the Ubisoft server is not available at this time"
My game has run fine up to this point with all modes. The only thing that I know of that changed recently is Windows downloaded and installed it's "Anniversary Edition" updates. I'm not sure how this could relate but it's the only thing I can think of that changed on my computer about the same time this problem started.
It's been 5 months now that I can't even get to play the multiplayer game and it's starting to get on my nerves. I've tried everything yet nothing works.
More strikening is the fact that I can connect on multi with all the other games except ACR...... It says I have to connect on Uplay and while I start it it's stucked on a black screen saying :Connecting to Uplay please wait.