APF-4-REGISTER_IPADD_ON_MSCB_FAILED: MSCB (mobile station control block) represents your clients. This means that a client is trying to pass traffic, but the controller is yet not ready for it. These messages are generated when the controller gets an ARP request from a client and it hasn't added the client's IP address to its client list. Once it does, everything should be fine.
Verify if you have “DHCP Required†option checked on your wlan (ssid) and if you do then disable it as this normally causes this error.
APF-1-CHANGE_ORPHAN_PKT_IP
This relates to the message above. This means that the client initially had one address which was cached on the WLC and then it came back across the WLC with a new different address, could be that it's not receiving a DHCP address and gets the 169.254.x.x Windows default IP, or like the Iphones it tries to stick with whatever ip address it had previously. Possible driver issue on the client and or dhcp required option. As you are seeing errors due to your clients I would suggest fixing the eap timers on the controller for your clients. This is give better stability to your clients as it will give more time to client to exchange information with radius server.
