If you cannot log in with your user in WLC, you can first check the password reset page.
If you still cannot log in, check the output on the console screen. You may have accidentally selected for user login with user authentication over radius. In this case, you may get a RADIUS authentication failed error as follows.
To switch to local user authentication:
1) All ethernet cables are disconnected. This disconnects WLC from the Radius server. Since radius can’t find the server anymore, it will look at the locale second.
2) Login to the system with the current user/password information. (See password reset page if you don’t know)
After entering the system, the user authentication priority is checked below.
Change the user authentication priority as follows.
(WLC) config>aaa auth mgmt local radius
User authentication priority is checked again.
The configuration is saved and exited.
Notes to Myself 