Cisco has released a new Engineer Special for the 6.x WLC code; 6.0.196.159
You will have to request this code from Cisco TAC as you will not find this on CCO. Cisco TAC stated 6.x release is tagged as software advisory. They are not recommending this code and if you have it installed you should apply the latest Engineer Special release until the 6.x maintenance release is released. The 6.x maintenance release is expected end of July / early August.
If you have 6.x running today Cisco TAC has advised the following path:
1) Down grade to 5.2.193.0 (ED)
2) Upgrade to 7.0.98.0 (ED)
3) Upgrade to 6.0.196.159 (ES)
AS_4200_6_0_196_159 is a build from 6.0.196.0, and it is an engineering special that resolves the following additional caveats:
CSCta13941 - AP rejecting association request with status code 13
CSCtb02136 - AP with AP Groups and HREAP will not broadcast SSID
CSCtb20125 - CCMP errors on key rotation
CSCtc73503 - Radios are showing Tx power level 0
CSCtd28542 - WLC crash on emWeb due to AP config change
CSCtd97011 - Radio core dump: Neighbor Discovery frames stuck
CSCte19262 - Client Deauthenticated – “Unable to locate AP 00:00:00:00:00:00”
CSCte55219 - radio core dump due to large # of uplink frames in inprog queue
CSCte55458 - Web-Auth: Web page takes a long time to display under heavy load
CSCte62815 - 5508 not passing OSPF Multicast traffic
CSCte78472 - Invalid PHY rate returned on ADDTS response
CSCte81420 - Crash in process: "Dot11 driver "
CSCte89891 - AP doesn't transmit beacons
CSCte92365 - Auto Immune - AP side
CSCte93549 - The dot11a radio not able to pass traffic, tx queue getting filled.
CSCte96140 - Ethernet bridging breaks when the Ethernet interface of AP 1242 flapped
CSCtf23682 - 5508 - AP cannot join with Multicast MAC as gateway (checkpoint)
CSCtf34858 - Clients unable to pass broadcast traffic
CSCtf69598 - Memory leak in AP on CCKM Failure
CSCtc57611 - Delay in Music on Hold on 7925 with HREAP AP CSCtg45014 - CT5508 - CAPWAP Control traffic has incorrect DSCP marking.
CSCtg71658 - Ap power level reset to 0 when upgrading from 5.0 to 6.0.196.158
CSCtd43906 - J: RAP not transmitting after coming up; when shut due to radar
*ENGINEERING SPECIAL USE DISCLAIMER*
The Engineering Special fix supplied herewith is a Temporary Software Module which has undergone limited testing. This temporary software module is provided “AS-IS” without warranty under the terms of the END USER LICENSE FOR THIS PRODUCT. Please use this software at your own risk. The intention for this code fix is for you to use in your production environment until a released version is available.