Conquest of the Horde

I've been having this issue for several weeks now, and I have no idea where it came from or how I got it. But whenever I try to sign into WoW, I get a windows error message followed by in-game text. Needless to say, it's bugging the hell out of me.

I go through the motions of entering my password and logging in. It goes through the whole "authenticating, approving, handshaking, success, connecting" routine, but instead of going to the character select, I get this:

"Cannot stream required archive data. Please check the network connection."

WoW then tells me I have been disconnected from the server. Every. Single. Time.

I have tried everything I know to do, short of reinstalling the entire game. (Which I really don't want to do. Period) I have tinkered with the cache folders, I have renamed folders, moved folders. Taken WoW off my external hard drive and left it on the computer, only to move it back. I've disabled the firewall; disabled the anti-virus; disconnected from the internet, then connected back. I've been to Battlenet countless times. NOTHING WORKS.

So, I was wondering if any of you had encountered this problem, or know how to fix it. If anyone could help me with this, I'd be much obliged.

I'm running a PC with Windows Vista.

@Kretol

I know that several other folks have had this issue, so I've been waiting to see if any of them can help provide their experiences. I personally have not experienced it (aside from when I was first getting Cata to work) so am uncertain as to a resolution.
As some potential steps to take, you could try ensuring you don't have an Updates folder (and if you do, delete it). Furthermore, you could try making a backup of your Wow.exe, Wow.tfil, and Wow.mfil files and then decompress this archive into your WoW folder (root directory).

Decompressing those files solved the problem for me. I also deleted a file called "PlaceholderArchive.temp" in my Data folder, and copied the custom patch into both Data and enGB/US for good measure, then it worked like a charm and I can dance with Murcablo on GMI.

None of those solutions solved the problem. I'm still getting the error message, I still can't log onto WoW, and I'm getting damn frustrated.

I'm going to try connecting my computer directly to the router to see if it isn't an issue with the connection or the wifi signal. If that doesn't work, I'll just reinstall the damn thing.

Thanks anyway, though.

Reinstalling the game fixed the issue. I can log in again.

Sorry you had to resort to that. When I was first trying to get a Cata server to work, I had that happen a few times with various WoW torrents. Only solution was to eventually find one that worked properly.