A great little "feature" of Cisco's Identity Services Engine is that out of the box, the administrator account expires after 45 days if the password is not changed during that time. The documentation says that if you have trouble logging in you should click the "Problem logging in?" link and use the default administrative user/pass. This is of course ridiculous and does not work.
Below are the steps for properly resetting an admin password and for changing the security policy so the lockout doesn't happen again.