SEPM 12.1 with Cisco WLC 5.0

Hello, 

We are currently Implementing a NAC solution with LAN Enforcers and SEPM 12.1. We are having issues with integrating a Cisco 2106 wireless lan controller with this architecture. Is there a minimum firmware version that the Cisco wireless lan controller must have to support integration/communication with a LAN Enforcer? The cisco WLC is currently running firmware version 5.0.   The Radius server we are using is an ACS 4.2.

Thank you