If staggered-reboot has been configured when upgrading APs, the upgrade has to be cancelled and then performed again with the correct syntax as follows:
- Cancel the AP upgrade:
#device-upgrade cancel-upgrade all
- Run the command leaving out "staggered-reboot".
#device-upgrade rf-domain <rf-domain name> all
#device-upgrade rf-domain <rf-domain name> <AP model>
Use the "?" to find all the available "device-upgrade" command variants and select the one that best corresponds to your situation.