In OneNote for Win 10, the Word and Excel attachments inserted in notes are read-only, why? How to edit the attachments?
OneNote for Windows 10 runs in a separate sandbox. Unable to communicate directly with external programs.
OneNote's traditional attachments can be opened with local App, but they are impossible edit and save back to OneNote.
In order to be able to use editable attachments.
You can save attachments as new OneNote’s cloud attachments.
Then use Gem Menu for OneNote UWP add-in to open the cloud attachment for editing.
This solves the annoying problem that the OneNote for Windows 10 attachments have not been editable all along.
MAC: How to Enable/Disable Cloud File Attachment in OneNote (Apple Version)?
2019-3, OneNote UWP upgraded to 16001.11328.20100.0, starting to support opening traditional attachments for editing.