I have an iPhone and Windows Phone, and use OneNote on the web as well. Syncing to the iPhone and Windows Phone was working fine; two weeks ago sync to both phones stopped working. On the web, I can see all my OneNote documents fine. I haven't changed any settings on my Microsoft account nor on the two phones. I am not making huge changes to the content which would lead to conflicts.
The error on the iPhone is "Can't sync section: Quick Notes (Error 0xE00001AE)" and on the Windows Phone is "We can't complete this task. Try again. Error code: e00001ae".
On the iPhone I have deleted and re-added the Microsoft account, whereafter it synced exactly once, before having the same problem again.
On the Windows Phone, I cannot delete and re-create the Microsoft account (can only delete other accounts such as Google) and I cannot delete and re-add the OneNote app (seems to be part of Windows, cannot delete it).
On the Windows Phone I went to Settings -> Applications -> Office -> Reset Office. Now all my notes are gone from the phone, but it still won't sync, with the same error.
What can I do to debug this problem or resolve it?