Try deleting your WoW/Cache and WoW/Data/Cache folders. Also delete WoW/WTF/Account folder.
If the error still happens on login, can you:
If the error still happens on login, can you:
- ... paste the contents of WoW/Logs/connection.log in this thread?
- ... create a [url="http://pastebin.com/"><s></s>http://pastebin.com/ "paste" (be sure to set Public exposure to Unlisted) of contents in latest .txt file in WoW/Errors and then put the link to that paste in this thread?