As long as it goes with the game, it's not the games fault for this happening. Everyone run the exact same client and constant connection issues when the server is running fine and others are able to play would be your network setup or computer and that's pretty much end of.
I'd suggest looking into LordSuras post earlier in this thread taking from the help sticky regarding connection issues because ultimately it would be the exact same information I'd give anyone contacting me regarding this matter.
To me it sounds odd it would be the windows firewall at least since it either lets a program through or it doesn't, and in this case you are able to log on and play for a while before this happens to you.
If I were you I'd look into what sort of antivirus software you are using and look if that is the thing causing issues for you, all antiviruses has a disable function that lets either turn it off completely, or turn it on for 10-15 minutes. You should try to do exactly this in that case and see if FH works until it kicks in.
You should also check up so there's no other software or program that starts a while after your computer has been running that might interfere with your connection towards the game, so pretty much any software in general that shouldn't need to be on the computer.
You can always check so you have uPnP enabled in your router as well I suppose but in general, as said, read Suras quote through throughoutly and make sure you check up and try to do the things suggested in there, because it's not the game that's the fault in this case.
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