This is to help those who have had a rude awakening to find all their notes have disappeared!
From time to time your iOS device may seem to have deleted your stuff, but more likely; is that your device is running critically low on storage, and when this happens you will experience crashes and reboots.
Leading to your discovery that you need to retype passwords to websites that your Safari used to remember or even more disturbingly loosing all those precious notes. You may also realise as a plus point that storage space has freed-up on your device. Now here's the dreaded question "What was deleted?"
Well if your lucky hopefully nothing valuable. The iOS has a ridiculous way of handling storage and that is it fights for the very same storage partition to operate, that you are using to save your work too! Apple could make-life easier for its users and have dedicated a portion of your storage as a separate partition for your work and apps to function and a partition dedicated solely for the iOS to operate. But lets face it, this is Apple and they don't always do things the most logical way!
Now enough of that lets see if we can retrieve your notes.
As part of its clearing process it clears away your accounts, that you may have had linked to your iPad i.e. Gmail (Google Account) yahoo and so forth. And it may be that those missing-notes were linked to anyone of those accounts.
I'm using iOS 10.3.3 so your steps may vary.
All you need to do is the following:
Firstly (this step is only needed if your device has signed out completely from your Apple ID)-
1. Open "Settings".
2. Tap Apple ID section and sign back into your Apple ID
Secondly (the main part)-
1. Open "Settings".
2. Go to "Mail"
3. Tap it, now tap on "Accounts"
4. Tap on "Add Account" now type in the details to all the other accounts your iPad was previously linked with (i.e. Gmail, Yahoo and so on.
5. After completing the steps above, go and open up your "Notes App" and as long as you re-linked your iPad back with all the previous accounts you had it registered to, all your notes should be back in place.
6. If that hasn't worked then move onto the next step.
Thirdly (extra steps to try)
1. Open "Settings".
2. Go to "Mail"
3. Tap it, now tap on "Accounts"
4. Now tap on each account you had created, one by one, and activate "Notes" within each one.
5. After completing the steps above, go and open up your "Notes App" and as long as you have reactivated "Notes" in each one, all your notes should be back in place.
6. Wherever it's worked for you or not please comment.
