We had a Cisco 5508 Wireless LAN Controller in our HQ building which was managing 26 Aironet 3501I access points. It was running controller software version 7.4.110 with 50 AP base-licenses.
We decided to add 20 more APs in order to improve the wireless coverage. So we got new Aironet 3702I access points.
According to Cisco Wireless Solutions Software Compatibility Matrix controller software version 7.4.110 does not support the 3702I access points. So we had to upgrade the controller software.
You will see a log message like this in case the controller software does not support the more recent access points: “Discarding primary discovery request in LWAPP from AP xx:xx:xx:xx:xx:xx supporting CAPWAP”
We downloaded the most recent version of software (18.104.22.168 at the time of writing this post) and downloaded it to the controller. We rebooted the controller and licenses were gone!
We tried to re-install the license backup file we had made before upgrading but it FAILED!
We switched back to the previous software version immediately and rebooted the controller. The Licenses were back then.
We guessed that it was because we had made a major upgrade (from version 7.4.x. to 8.2.x) so we decided to upgraded to the very first version of controller software where Aironet 3702I APs were supported for the first time. We upgraded to controller software version 7.6.110 and this time it was successful.
I don’t know if Cisco guys approve this workaround but it worked for us.