If you are seeing this error during access GUI of the AP, I would suggest upgrade the AP again to 5.0.1.1066 as I doubt upgrade may have corrupted SSL certificates Or you can reset of the AP. best option open ticket with support to nailed down RCA
If you are seeing this error during access GUI of the AP, I would suggest upgrade the AP again to 5.0.1.1066 as I doubt upgrade may have corrupted SSL certificates Or you can reset of the AP. best option open ticket with support to nailed down RCA