Same here. I'm using OneNote 2016 and 2013 on different computers (both Windows) and both seem to be affected. The Windows store app and the mobile app (android) are also affected.
I've tried everything that i can think of. I've cleared the cache, made new notebooks, deleted old ones, deleted pages, deleted sections, saved offline copies, re-synced offline copies to the Skydive, etc. Even copying the individual elements from the affected
notebook to a new notebook resulted in the new notebook experiencing sync issues.
Opening the notebook in OneNote online doesn't help much either. Strangely enough, if i play around with it enough I can get it to open the pages. Once i do get it open i can see all the content intact but if I try to modify it, the changes won't be synced.
The desktop version also behaves like this. Sometimes I can get the pages to sync to the other app. This is usually slow and the "incomplete sync" error is displayed the whole time. After some time the sync error did disappear but once I clicked on the notebook,
it tried to sync and the error reappeared. If I click off of it to another notebook the error would disappear.
I was watching my internet usage with task manager and i could see that it would sync for about 10 seconds then stop. I could then get it to continue to sync before it would stop again. Its almost like its timing out and stops syncing. I'm not sure if this
is normal or if its even relevant to the issue. Thought i would just put it here if it helps to solve the issue.
I also tried creating a new notebook and seeing if it syncs. For the most part, it can sync fine. It can even sync ink but it runs into issues when I either copy things from the affected pages into it or it seems to cause issues if I add tags like check
boxes. Once the section gets a sync error I usually can't recover it. Even this is inconsistent.
There is some hope; I was able to recover one of my notebooks twice by deleting the affected sections. This was my main notebook which contained the Quick Notes section. Now it only contains that Quick Notes section and the sync error is gone. I'm reluctant
to try too much with that section though because i fear that i might loose it.
I'm at a loss for what is going on. Hopefully this was just some glitch and it will be resolved soon.