you can find it from:

http://www.cisco.com/en/US/docs/wireless/controller/message/guide/msgs6.html

Error Message %LWAPP-3-RX_ERR3: Received LWAPP packet with invalid sequence number

(got [dec]expected [dec]) - from AP [hex]:[hex]:[hex]:[hex]:[hex]:[hex]

Explanation LWAPP packet sequence mismatch has occurred, LWAPP packet was dropped. AP may not function as expected.

Recommended Action No action is required.