CSCvo92324 - AP will not join back to WLC - DTLS Connection not found

[William Foster]

The AP with the issue is not a 1850 series it is a AIR-AP3802I-B-K9. We are luckily running 2 5520 controllers. I am not sure why this bug is effecting only one controller and not the other when they were both upgraded the exact same way. 

[Leo Laohoo]

This status is still deemed as "OPEN".
However, have you tried getting the AP to join a controller running, say 8.3.143.0 as an "intermediate"?

[William Foster]

That's another strange thing. I did roll back my upgrade and I still had the same issue.

[Leo Laohoo]

Remote into the AP and delete the CAPWAP image and reboot the AP. Force the AP to boot the RCV image.