NAC Manager "State" column states: "There is no method to authenticate user, <username> discarding request"
Extreme Access Control (EAC)
NetSight NAC Manager
AAA configuration of NAC manager is not configured to handle authenticate type attempted, or username attempted.
In NAC Manager click menu options "Tools" > Management and Configuration > Advanced Configuration
Drill into AAA configurations
Click the AAA configuration in use
If basic AAA configuration make sure a RADIUS server is configured.
If an advanced AAA configuration is in use verify there is a configuration line to handle either the authentication type or the username that was attempted. Each authentication attempted to NAC manager must have a defined action in the AAA configuration. This can be handled either by 802.1x type, or by username, but if any authentication request does not have a defined action in the AAA configuration then you'll receive the above error.
Make sure that advanced configuration is enabled.
If LDAP test works but LDAP is not working from the NAC (This is assuming the customer is not using proxy-radius to a radius server), go to Tools->Management and Configuration->Advanced Configuration-> then select your working NAC configuration that includes the rule set.