I have enabled a local user with local authentication which does not seem to work. What can I change to make local authentication work? How do I go about turning Radius off and enabling Local Authentication?

The MultiAccess does NOT support Local Authentication for Dial In users. The function of the "Local User" menu is for adding users for "linux level" access (logging in via SSH or via keyboard and monitor).

All Dial-in users must be defined/listed in a RADIUS Server Database. The RADIUS Client points to the RADIUS server. The RADIUS Server (and it's database of users) can be external to the MultiAccess or the RADIUS server can be the RADIUS Server provided within the MultiAccess.