When I created my account to apply my beta key, naturally I gave it a strong password.
When I tried to log in to the game, it rejected my password for containing illegal characters - as stated at http://www.ageofwushu.com/forum/viewtopic.php?f=3&t=621:
When selecting a password for your account, do not use any special characters, such as !@#$%&*.
This will prevent you logging into your account.
To reset your password, go to http://member.us.woniu.com/find/find_pwd.jsp, at which point you will be asked for username and email address, and say - like I did - "wtf, I don't have a username!?"
When you create a Snail account via the Age of Wushu beta site, it creates your username as your email address but in all caps. So enter:
Email Address: firstname.lastname@example.org
Wait for your password reset mail, and change it to a weak password with no special characters in it.