We would need more information about your infrastructure:
- Do you have a single controller or multiple controllers?
- You would see this message from a device where it finds the first controller, but the LMS-IP in the access point's ap system profile in ap-group points it to another controller that does not exist. When the access point finally reboots because it cannot find that second controller, it comes up and reports that it did not find the second controller, to the first controller. Without knowing your setup, we cannot determine if that is your issue.
- The "show ap" commands do not work for devices that are not currently up and running on a controller, so that might explain why those commands fail...