Fix OneNote sync error 0xE40105F9 (Unsupported Client Build)

According to Microsoft, the OneNote sync error 0xE40105F9 occurs when you are using an outdated version of OneNote which is no longer supported by the Microsoft server. To get this problem resolved, you should update OneNote to the latest version released by Microsoft. Follow the suggestions written below if OneNote is not syncing. Let’s talk about these fixes in detail.

1] Update Microsoft Office

Microsoft Office is a complete suite that comes with different Office apps, including Word, PowerPoint, Excel, OneNote, etc. Because the OneNote desktop app is a product of Microsoft Office, you should update Microsoft Office to the latest version in order to update OneNote. The following instructions will guide you on how to update Microsoft Office:

It will be better if you enable the automatic updates in Microsoft Office so that all your Office apps remain up to date. The steps to enable automatic updates in Microsoft Office are written below:

2] Update OneNote for Windows 10

If you are getting the error code 0xE40105F9 on OneNote for Windows 10 app, update it to the latest version. The steps to do this are as follows:

3] Try other fixes to resolve the sync error

If after updating OneNote to the latest version, you are still getting the sync error 0xE40105F9, you can try some other fixes to resolve the error.

Force sync your notebooks

You can try force syncing your OneNote notebooks. The steps for the same are written below:

After that, OneNote will start syncing all your notebooks. Also, make sure that you have selected the Sync automatically option to avoid syncing your notebooks manually.

Create a new notebook

If a particular notebook is giving the sync error in OneNote, you can try this method. Create a new notebook and copy all the content from the affected notebook to it. Now, OneNote will sync the newly created notebook automatically, after which, you can delete the old notebook.

Delete OneNote cache

Sometimes a problem occurs due to corrupted cache files. Deleting OneNote cache files can also fix the syncing issues. Before clearing the cache files, it is recommended to backup your unsynchronized notebooks. Read: Fix OneNote Not working, Not opening, Problems, Errors, Issues.

How do I fix OneNote sync error?

It is important that you should have an active internet connection in order to sync your OneNote notebooks. If you are experiencing OneNote sync errors, you can try some common solutions, like signing out from OneNote and signing back in, force syncing your notebooks, deleting the OneNote cache files, etc.

What happens if you delete OneNote cache?

OneNote cache files act as temporary storage for offline edits. All the changes that you make in your notebooks offline remain stored in the cache files until Onenote syncs your notebook to the server. If you delete the OneNote cache, all your unsynchronized data will be deleted. Therefore, it is better to backup your notes before deleting the OneNote cache. Hope this helps. Read next: Fix OneNote sync error 0xE4020045.