What is the reason for this error in the ap7522 upgrade？

[huhuan]

[huhuan]

I rebooted it many times but it didn't work

[RobertZ]

Since secondary the partition is in state "unknown" please first upgrade the AP with firmware 5.9.1.0-029R. If that successful than proceed with upgrade to firmware 5.9.5.0-007R.

[Ron_Galien]

Hello Huhuan,
The cause of this issue is most likely due to firmware image not properly loaded in the system partition.

Reboot the APs which are having the issue, and try to push firmware upgrade again.

Hope this helps