Mists of Pandria not launching at all

Hello, I just finished downloading MoP 5.4.8 and I tried running it (wow.exe). And I get the following message :

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

I tried running as administrator, disable both antivirus and Windows Firewall, nothing helps.

Thanks for the help in advance :D

1) close your Torrent client and move your MoP folder away from your Torrent's download destination
2) now right click on MoP folder> Properties> remove "read-only"