Microsoft C++ Runtime error

Hello, I'd like to say first that if this has been answered else where, I'm sorry, but I couldn't find it on any poosts or stickies.

Ok, so upon launching the WoW client, which opens the launcher first, it says the usual "Data for the next patch is available to download...". When I click "Play" and the actual client begins to load, I get a message:

"Microsoft Visual C++ Runtime library
Runtime error!
Program: C:\ Program Files\World of Warcraft\BackgroundDownloader.exe
This application has requested the runtime to terminate it in an unusual way.
Please contact the application's support team for more information."

Upon clicking "Ok", I recieve this:

"Blizzard Dowloader
Blizzard downloader has encountered a problem and needs to close. We are sorry for the inconvenience."

Send error report/ don't send, etc etc.

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I can't go into the actual program files and launch the downlader there. Same message.
I can log into the game and play as normal, just wondering what I'll do for patch day. Mirror it? =S
Any idea how to fix it? =(