AP Admin Status Getting Disabled Automatically After Upgrade to 7.4

Question

Hi,
We were using wlan controller 5508 firmware 7.0.235 and decided to upgrade our firmware because we wanted to use some new AP models. We upgraded the controller to the 7.4.110.0 and after that a problem started. Some of the AP are becoming ADMIN DISABLED and they are getting down, this is happening all day and random times. I need to manually getting them admin enabled so we can use them. What can cause this problem?
This happens in APs in Flexconnect mode.
Regards.
Wlan Cont
AIR-CT5508-K9

Answer 1

Problem happens with these AP : AIR-LAP1041N-E-K9 
We have many AP it is very difficult which AP to debug, everytime different AP is getting disabled. I've also configured syslog but also I do not receive any syslog message to my syslog server. Should I upgrade to 7.5?
Log from AP after disabled...
    Console logging: level debugging, 39 messages logged, xml disabled,
                     filtering disabled
    Monitor logging: level debugging, 0 messages logged, xml disabled,
                     filtering disabled
    Buffer logging:  level debugging, 39 messages logged, xml disabled,
                    filtering disabled
    Exception Logging: size (4096 bytes)
    Count and timestamp logging messages: disabled
    Persistent logging: disabled
    Trap logging: level emergencies, 12 message lines logged
        Logging to 10.0.2.47  (udp port 514, audit disabled,
              link down),
              0 message lines logged,
              0 message lines rate-limited,
              0 message lines dropped-by-MD,
              xml disabled, sequence number disabled
              filtering disabled
        Logging Source-Interface:       VRF Name:
Log Buffer (1048576 bytes):
*Mar  1 00:00:10.770: %SOAP_FIPS-2-SELF_TEST_IOS_SUCCESS: IOS crypto FIPS self test passed
*Mar  1 00:00:10.773: *** CRASH_LOG = YES
*Mar  1 00:00:11.073: Port 1 is not presentSecurity Core found.
Base Ethernet MAC address: D8:67:D9:FC:00:D6
*Mar  1 00:00:12.424: %SOAP_FIPS-2-SELF_TEST_RAD_SUCCESS: RADIO crypto FIPS self test passed on interface Dot11Radio 0
*Mar  1 00:00:13.507: %LINK-6-UPDOWN: Interface GigabitEthernet0, changed state to up
*Mar  1 00:00:14.518: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0, changed state to up
*Mar  1 00:00:16.503: %SYS-5-RESTART: System restarted --
Cisco IOS Software, C1040 Software (C1140-K9W8-M), Version 15.2(2)JB2, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2013 by Cisco Systems, Inc.
Compiled Mon 29-Jul-13 12:06 by prod_rel_team
*Mar  1 00:00:16.503: %SNMP-5-COLDSTART: SNMP agent on host Antalya is undergoing a cold start
*Mar  1 00:00:16.570: %LINK-5-CHANGED: Interface Dot11Radio0, changed state to reset
*Mar  1 00:00:17.567: %LINEPROTO-5-UPDOWN: Line protocol on Interface BVI1, changed state to up
*Mar  1 00:00:28.630: %CAPWAP-3-ERRORLOG: Could Not resolve CISCO-CAPWAP-CONTROLLER
*Mar  1 00:00:28.632: %LWAPP-3-CLIENTERRORLOG: LWAPP LED Init: incorrect led state 255
*Mar  1 00:00:28.633: bsnInitRcbSlot: slot 1 has NO radio
*Mar  1 00:00:28.657: %CAPWAP-3-ERRORLOG: Binding Config Initialization failed for binding 1
*Mar  1 00:00:29.190: Starting Ethernet promiscuous mode
*Mar  1 00:00:29.396: %SSH-5-ENABLED: SSH 2.0 has been enabledlwapp_crypto_init: MIC Present and Parsed Successfully
*Mar  1 00:00:44.681: Logging LWAPP message to 10.0.2.47.
*Mar  1 00:01:03.711: %CAPWAP-3-ERRORLOG: Could Not resolve CISCO-CAPWAP-CONTROLLER
*Mar  1 00:01:13.713: %CAPWAP-3-ERRORLOG: Selected MWAR 'COLINS-WLC'(index 0).
*Mar  1 00:01:13.713: %CAPWAP-3-ERRORLOG: Go join a capwap controller
*Aug 21 08:32:29.000: %CAPWAP-5-DTLSREQSEND: DTLS connection request sent peer_ip: 10.10.10.10 peer_port: 5246
*Aug 21 08:32:30.063: %CAPWAP-5-DTLSREQSUCC: DTLS connection created sucessfully peer_ip: 10.10.10.10 peer_port: 5246
*Aug 21 08:32:30.063: %CAPWAP-5-SENDJOIN: sending Join Request to 10.10.10.10
*Aug 21 08:32:35.063: %CAPWAP-5-SENDJOIN: sending Join Request to 10.10.10.10
*Aug 21 08:32:35.154: Starting Ethernet promiscuous mode
*Aug 21 08:32:37.005: %LWAPP-4-CLIENTEVENTLOG: OfficeExtend Localssid saved in AP flash
*Aug 21 08:32:37.025: %LINK-5-CHANGED: Interface Dot11Radio0, changed state to administratively down
*Aug 21 08:32:37.224: %CAPWAP-5-JOINEDCONTROLLER: AP has joined controller COLINS-WLC
*Aug 21 08:32:37.273: %LWAPP-4-CLIENTEVENTLOG: No Flex ACL map configuration file to load. Connect to controller to get configuration file
*Aug 21 08:32:37.275: %LWAPP-4-CLIENTEVENTLOG: No Flex ACL map configuration file to load. Connect to controller to get configuration file
*Aug 21 08:32:37.275: %LWAPP-4-CLIENTEVENTLOG: No LS Flex ACL map configuration file to load. Connect to controller to get configuration file
*Aug 21 08:32:37.276: %LWAPP-4-CLIENTEVENTLOG: No Central Dhcp map configuration file to load. Connect to controller to get configuration file
*Aug 21 08:32:37.279: ac_first_hop_mac - IP:192.168.31.1 Hop IP:192.168.31.1 IDB:BVI1
*Aug 21 08:32:37.279: Setting AC first hop MAC: 0024.14d9.f118
*Aug 21 08:32:37.965: %WIDS-6-ENABLED: IDS Signature is loaded and enabled
*Aug 21 08:32:47.905: %CDP_PD-4-POWER_OK: Full power - LOW_POWER_CLASSIC_NO_INJECTOR_CONFIGURED inline power source