If your WoW Launcher.exe for Mist of Pandaria (MoP 5.0.4) gives you the error on loading "Failed to read a required file" then hit CTRL+ALT+DEL, start the task manager, find the Agent.exe and hit End process.
Once this is done you will be able to start your client. If again you have problems run the Launcher.exe as administrator.
Another fix you could try is to do the following:
1) Renaming my WTF folder. (any name)
2) Running wow.exe
3) Logging in to the game. (All the way, actually entering the world with a character)
4) Exiting game.
5) Running the launcher.
Another thing which you could do is go to the location of the Agent.exe and delete the file. On my Windows it was located at C:\ProgramData\Battle.net\Agent Just delete the whole folder, or better yet, zip it and move it before you delete it, to have a backup of it.
Another thing you could do if you have trouble download the MoP beta updates is to delete the updates folder in your WoW directory.
The problem was probably caused by the blizzard's development updating team, read the blue post here
Once this is done you will be able to start your client. If again you have problems run the Launcher.exe as administrator.
Another fix you could try is to do the following:
1) Renaming my WTF folder. (any name)
2) Running wow.exe
3) Logging in to the game. (All the way, actually entering the world with a character)
4) Exiting game.
5) Running the launcher.
Another thing which you could do is go to the location of the Agent.exe and delete the file. On my Windows it was located at C:\ProgramData\Battle.net\Agent Just delete the whole folder, or better yet, zip it and move it before you delete it, to have a backup of it.
Another thing you could do if you have trouble download the MoP beta updates is to delete the updates folder in your WoW directory.
The problem was probably caused by the blizzard's development updating team, read the blue post here
