Can't start WoW MOP

Hi,

I downloaded MOP but when i start on WoW.exe it appears every time mesage " 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 " and i cant start playing.

What to do ?

I have same problem.

It is due to permissions, see the following image: http://i.imgur.com/5wWKUL6.gif .

It worked ! thanks