Recently, a customer I work with asked me to investigate why the tabs in their shared OneNote notebooks were disappearing. It is especially prevalent when they moved to OneNote 2016. The cause as it turned out was something called Windows Deduplication. At its simplest, it is a way to reduduplicate files and similar streams of data on a disk. It is a form of compression at its simplest which is to say it is a mechanism to allow you to stick more stuff on a computer or server disk. What we found was the deduplication was corrupting the OneNote index (toc) on the server and each time someone went to make changes to the OneNote file on the server. Tabs would start disappearing for other users when multiple users were editing the files. When we enabled the exception for OneNote files in the data deduplication feature and then moved the OneNote files from one folder to another and then back (which is required to de-optimize the files), the problem went away. To resolve this problem you will likely need your administrator involved:
- You will need to set an exception for the OneNote file extensions in Windows Server 2012 Data Deduplication.
- Here are some details on configuring that with PowerShell. See the “Modifying Data Deduplication volume-wide settings” section.
- You will need to exclude these extensions: *.one, *.onebin, *.onetoc2
- Next, have everyone close OneNote on their systems.
- Finally, you will need to “deoptimize” (or, and I love this, de-dedup) the files. To do this, you will create a folder somewhere in the shared folder, move all the files in the OneNote folder to that location, then move them back.
NOTE: Nothing needs to be done on the clients, they will just work the next time the users launch OneNote. You might notice the tabs will still initially appear to be missing, but they will re-index and come back. This might take a few minutes depending on how many tabs there are.
Once completed, you should find that your tabs are no longer disappearing.