Apprentice Users

Apprentice users will not have an account containing licenses so Apprentice users cannot log into the License Administrator (hkey).
When Houdini Apprentice is first launched, the user will be prompted to install the free license.

Indie, Education and Commercial users

Try resetting your password at www.sidefx.com/password/reset.
By resetting the password, it will unify the login credentials for both the website and licensing system.