Edit: it lets me join games, but kicks me and shows me that error message within a couple seconds of joining?
Please help!
Maybe the folks at /r/battlefield_4 can help you. Thats the official subreddit.
Uninstall punkbuster, and redownload/reinstall it. Then you updates it and try again. If it still dosen’t work, its probably the firewall that blocks the pnkbstrA- or B.exe. Allow those, and you should be good to go. Those steps did it for me.
Did it work? (RE: vermund2k’s post)
Yep, google for pbsetup and do an update for your BF4 install
Um, then what’s this one?
The non official 
I heard people say that this is a troll subreddit but I wouldn’t call it that. /r/battlefield_4 is just way more popular and has more traffic.