Need help

I have a problem with logging in to my account

that is the msg that i have got :

This application has encountered a critical error:

ERROR #134 (0x85100086) Fatal Condition
Program: C:UsersasusDesktopgameswow 80WoW..exe

CMap::LoadWdt() failed WorldMapsNorthrendNorthrend.wdt

need help; what I have to do?

You download the game again and after it completes downloading you perform a hash check to make sure it's actually 100% downloaded.