The hyperlink was blocked by OneNote

Dear komorebiBE, 

Thank you for posting your question to the Microsoft Support Community. 

The error message "Your administrator has blocked your ability to open this file type in OneNote" when clicking a hyperlink to a local folder (e.g., C:\Users) is likely related to security changes introduced in update KB5002714 for OneNote 2016. This update strengthens protection against potentially unsafe links, and unfortunately, it may also block folder paths, even though they don’t have file extensions. 

You can try the following suggestions: 

1. Use a shortcut file (.lnk) 
   Create a shortcut to the folder and insert a hyperlink to that .lnk file instead.
2. Use OneNote for Web 
   Try opening the notebook in OneNote Web, folder links may work there without restriction.
3. Check with your IT administrator 
   If you're in a managed environment, ask your admin to review Group Policy settings under: 
   User Configuration > Administrative Templates > Microsoft OneNote > Block file extensions for hyperlinks 
   While folders don’t have extensions, this policy may still affect how OneNote handles them.
4. Uninstall KB5002714. 
   If the issue critically affects your workflow and no policy override is possible, you may consider uninstalling the update via: 
   Control Panel > Programs > View Installed Updates > KB5002714 > Uninstall

This behavior is part of a design change aimed at improving security in enterprise environments. While it helps reduce risks, it may also impact usability in certain scenarios. If folder hyperlinks are important to your workflow, we strongly encourage you to submit feedback via Help > Feedback in OneNote. The more users report and upvote this concern, the more likely it is that Microsoft will review and consider improvements in future updates. 

If this answer helps, please consider marking it as Answer. This not only highlights the solution for others with the same issue, but also helps bring more visibility to the topic — increasing the chance that Microsoft will take it into account. 

Best regards, 

Thu-D/Microsoft Community Support Specialist

Hi @komorebiBE,

I encountered this issue as well. After some investigation, I found an official Microsoft support article that explains the behavior:

https://support.microsoft.com/en-us/office/error-your-administrator-has-blocked-your-ability-to-open-this-file-type-in-onenote-when-selecting-a-link-to-certain-folder-paths-1290dd67-c04e-460f-a474-13c2b1baa69e

According to the article, OneNote blocks certain folder path links (such as file:// or mapped drives) due to security policies. The current status is listed as "Investigating", and Microsoft has stated:

We are working on a fix for this issue and will provide an update when it becomes available. In the meantime, the only workaround is to copy the network folder (UNC path) or local folder path and paste it directly into File Explorer to access the folder.