From late April to late May, Microsoft will roll out a change to OneNote that prevents files on their Blocked list from being opened, similar to what is already done in Outlook, Word, Excel and PowerPoint. If a blocked attachment is clicked on, a dialog box will let them know that their administrator has blocked them from opening the embedded file. For more information, see OneNote will block embedded files that have dangerous extensions.
This change only affects OneNote for Microsoft 365 on devices running Windows. The change doesn’t affect OneNote on a Mac, OneNote on Android or iOS devices, OneNote on the web, or OneNote for Windows 10.