Cause for this "Sensor receive failure" on AP?

[jonathan.maxwell]

Hello tech gods!

QUESTION: What is causing this "Sensor receive failure"?

DEVICE DETAILS: Cisco AIR-AP2802E-E-K9 : IOS 8.5.161.6

Cisco AIR-CT3504-K9: IOS 8.5.161.6.

Thank you!

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Mar 26 19:43:37 NCI: E1: Sensor receive failure (0), 0
Mar 26 19:43:37 NCI: E1: Fatal condition, shutdownNci needed, Receive Failure
Mar 26 19:43:37 NCI: CLEANAIR: Slot 1 error detected
Mar 26 19:43:37 NCI: I1: shutdownNci
Mar 26 19:44:00 NCI: I1: openSensor(slot=1)
Mar 26 19:44:02 NCI: I1: SensorApp=1.15.4
Mar 26 19:44:02 NCI: I1: SensorHdw=http://1.2.3.0
Mar 26 19:44:02 NCI: I1: Hardware Radio Band = [4890, 5935] MHz, BW=150625
Mar 26 19:44:02 NCI: slot=1 mode=2 chanCnt=2 cw=3
Mar 26 19:44:02 NCI: chans: 108 112 0 0 0 0 0 0 0 0 0
Mar 26 19:44:02 NCI: I1: channel map channels: in=2 cloned=2
Mar 26 19:44:02 NCI: I1: Requesting MonBand [5550, 5550] bw=40MHz/0 ant=0xbc
Mar 26 19:44:02 NCI: I1: Monitoring (cf=5550, span=40), RadioUsage=3%
Mar 26 19:44:02 NCI: I1: dwell=20000us, update=1000ms, resBW=156249
Mar 26 19:44:02 NCI: CLEANAIR: Slot 1 enabled
Mar 26 20:45:16 kernel: [*03/26/2022 20:45:16.4500] Re-Tx Count=1, Max Re-Tx Value=5, SendSeqNum=214, NumofPendingMsgs=1
Mar 26 20:45:16 kernel: [*03/26/2022 20:45:16.4500]

[Kasun Bandara]

Open cisco support (TAC) case for more details and troubleshoot.

[Flavio Miranda]

Hi

 Mostly probably a Bug. One documented bug CSCvh57266 treat a very similar message on 3800 AP with 8.5(107.79), not far away from your scenario. 

 In the WLC, WIRELESS Tab, CleanAir, you can disable CleanAir a little bit and observe the logs.  

[Rich R]

Almost definitely a software bug - possibly already fixed - so consider an upgrade for a start:

https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/200046-tac-recommended-aireos.html#anc9