Question:
With Mac OS version of OneNote, the Word and Excel attachments inserted in notes are read-only, but they can be modified on both the phone end and the pad, why?

OneNote General Attachment 
When we drag and drop files from MAC Finder to OneNote, they become attachments with medium icons.
This is the ordinary attachment.

The synchronization problem with OneNote is the most frequently asked question on the network. Not one of them.

The main complaint here is the synchronization around onedrive.com.

After April 2018, the OneNote for MAC began to add paid features.

When your account is a free account, the following features are not visible.
You can't use it.

Only if your account is a paid subscription of 365 accounts, the following features can only be seen, can be used.

Question:
Where is Mac OneNote's notebooks saved?

Question:
After deleting a notebook on onedrive.com, why does this notebook name still shown in the list of more notebooks in OneNote client?

How can I completely remove these deleted notebooks?

Question:
I cannot find any backup or export feature in my OneNote. How to backup notebooks from OneDrive?

Question:
From 2017.8.1, All OneNote clients cannot sign in, or cannot create notebooks, or cannot create sections.

Question:
How do I turn of auto-capitalization in OneNote on Windows 10?

Question:

How can I export all notes from Mac Notes.app and import into OneNote?

Question:
Now, all of my OneNote Apps cannot sync this notebook any more after I change the notebook name on OneDrive.com. How to make OneNote Apps sync this notebook again?

Question:
Sometimes, when you open your OneNote, you will find you have lost some notes. How to prevent the OneNote lost notes?

Question:

Every time I open OneNote, I have to sign in again in Mac.  OneNote is always asking me to sign in.  Every single time I boot up.  If I restart OneNote after signing in, it will ask me again for sign in again.  

Question:

Today, when using OneNote for Mac my MacBook Pro crashed. After rebooting, it told me OneNote had caused the crash. Now, everytime I open OneNote, the app crashed immediately. I've tried re-installing through the App Store and removing caches but it keeps crashing on start.

What to do? Most important is there are a lot of unsynced changes I cannot afford to lose...