The iOS 9 upgrade bug... and fix!

Dear iPad & iOS users, this week my wife came across the "iOS 9 bug update" and was afraid to loose all her data. Her iPad asked if she would be keen on upgrading to iOS 9. She was not aware of the potential issues and did not make a backup before. Why should we, when the iPad suggests the upgrade in such an informal way? This should not be rocket science.

Here is the fix I was able to perform. I wrote this blog post, because I did not find the solution on the Internet and like to share it.

The issue

After upgrading to iOS 9, the iPad rebooted, showed a slide to continue, and then froze. There was no way to boot the device correctly. Every reboot led to this same slide and froze. Even more, iTunes refused to make a backup or to install again iOS 9.

The solutions available on the Internet

None of them worked for me. E.g. http://www.techtimes.com/articles/86342/20150919/apple-addresses-ios-9-slide-to-upgrade-issue-heres-what-to-do.htm

My fix

Here the walkthrough, it is really easy.

1) disable the location feature on iCloud.com for the device.

2) Download the iOS 8 update for your device
http://osxdaily.com/2015/08/13/ios-8-4-1-update-ipsw-download/
Expect to download a 2Gb file.

3) iTunes
Connect the iPad to your laptop.
When it is recognized on iTunes, click on the "Update" button pressing the Alt key simultaneously (this key is also called the option key). iTunes will open a window and let you select the OSX update file.
The update file is designed to update from a lower OSX version; actually we are making a downgrade, but it worked like a charm for me.

After a device reboot, the iPad asked for my wifi credentials, then my wife's Apple ID and everything was hopefully back and working.

Do backup!

My biggest takeaway is that regular backups are making sense and can save your life (or at least your time). 

Although, a 32Gb backup is too big for my laptop, I chose to store the backup on an external hard drive. 
I do not know an easy way to change the path on iTunes, so I moved the backup directory to an external drive (~/Library/Application Support/MobileSync/Backup) and I created a symbolic link to the HD using a shell command. In my case:
cd /Users/olivier/Library/Application Support/MobileSync
Then
ln -s /Volumes/HD_backup/Backups_mobile ./Backup
Where HD_backup is your external HD name and Backups_mobile the destination directory.

Enjoy your iPad, and iOS 8 ;-)