The Game Won't Start

I have downloaded the MIsts Of Pandaria expansion and for some reason it won't start . Every time i try starting it , a message pops out and says : "Data/enGB/wow-update-enGB-18273.MPQ: World of Warcraft can’t make a required change to an archive file. Be sure you have write permission for the World of Warcraft folder or try running the game in administrator mode. For more information, see: https://battle.net/support/article/6910"

Someone please help as soon as possible

Thanks

in 10 hours no one could help this guy?...
follow these steps:
1) Restart your PC
2) close your Torrent client and move your WoW folder away from your Torrent's download destination
3) now right click on WoW folder> Properties> remove "read-only"

Thank you! Had the same problem and this worked for me :)