If I click okay the game runs fine but it's kind of annoying that this happens every time I boot the game up and log in.
I tried using the wow repair tool with no success then tried doing it with mods disabled, wtf and cache folder deleted I also rebooted my pc but it still happens.
Here's a screencap of the error. http://i.imgur.com/pnpmLBD.jpg
I didn't know if theres a built in feature to upload images on the forums so I used imgur.