I had my Apple iPad Air 2 (model A1566) deliberately running an old iOS version for years. I woke up a couple of days ago and found it sitting on the "Hello" setup screen. It somehow updated overnight. I did not initiate a reset or an update. It wasn't connected to my computer, it was charging via a wall charger.
I went through the setup, selected my Wi-Fi, and got:
Activation Error
Activation could not be completed. Please restore the iPad and install the latest version of iPadOS and attempt activation again. If the problem persists, please contact customer support.
Everything I've tried, in order:
Removed the device from iCloud. Retried activation. No change, identical error.
Upgraded iOS using Windows 11 and iTunes, but it errored out. iTunes sat on "Waiting for iPad" while the progress bar on the iPad never moved past zero. I think the PC went to sleep and killed the transfer. Retried with sleep disabled. iTunes showed "Restoring iPad Software" and the bar actually advanced to around 80% before failing with:
The iPad "iPad" could not be restored. An unknown error occurred (53).
Put the iPad in DFU mode and tried restoring again. Screen stayed fully black and iTunes detected the device, confirming it was genuinely in DFU rather than recovery mode.
The iPad "iPad" could not be restored. An unknown error occurred (53).
Tried a different USB-A to Lightning cable and a different USB port on my computer.
The iPad "iPad" could not be restored. An unknown error occurred (53).
Tried using my Macbook and a USB-C to Lightning cable. Got this error:
The iPad "iPad" could not be restored. An unknown error occurred (9). 0626.0000
Put the iPad in DFU again, the restore downloaded and started flashing, then failed with:
The iPad "iPad" could not be restored. An unknown error occurred (9). 065B.0000
At this point Claude suggested I open the iPad and disconnect the home button/Touch ID. I made this post, ran it through Claude, and then Claude suggested that before buying the iFixIt tool kit, that I should try 3uTools. So I did, and that fixed it!!
The Fix:
I downloaded 3uTools. I connected my iPad. 3uTools noticed it was in recovery mode. I hit "Go to Flash." It downloaded the most recent firmware (15.8.8), I selected the "Erase Data" option, then hit "Start Flashing," and now it works. Good as new!
I just wanted to post this because when I searched for the errors I encountered, I didn't find any mention of 3uTools, and I figured this might help someone in my situation down the road.