NPS denied access to user event ID 6273 response code 21

I have 2 SSID's test1 and test2  they both use the same radius server.  When i connect to test1 i authenticate and everything is good.  when i connect to test 2  i see event id 6273 with response code 21.  An NPS extension dynamic link library (DLL) that is installed on the NPS server rejected the connection request.

both of these SSID's were working and now test 2 does not work.  To my knowledge nothing has changed on radius server and my wireless lan controller.

Any Idea's. 

Network Policy Server denied access to a user.

Contact the Network Policy Server administrator for more information.

User:

Security ID:NULL SID

Account Name:

Account Domain:

Fully Qualified Account Name:

Client Machine:

Security ID:NULL SID

Account Name:-

Fully Qualified Account Name:-

OS-Version:-

Called Station Identifier:

Calling Station Identifier:

NAS:

NAS IPv4 Address:

NAS IPv6 Address:-

NAS Identifier:

NAS Port-Type:Wireless - IEEE 802.11

NAS Port:1

RADIUS Client:

Client Friendly Name:

Client IP Address:

Authentication Details:

Connection Request Policy Name:Secure Wireless Connections

Network Policy Name:-

Authentication Provider:Windows

Authentication Server:

Authentication Type:Extension

EAP Type:-

Account Session Identifier:-

Logging Results:Accounting information was written to the local log file.

Reason Code:21

Reason:An NPS extension dynamic link library (DLL) that is installed on the NPS server rejected the connection request.

i have been working on this for a few days now and cant seem to find a whole lot of information on reason code 21.