Hi Angie55555,
This error might occur if the OneNote application is outdated. Kindly install pending updates and check if if the issue persists. If the notebooks that won’t sync are stored on OneDrive, try opening the notebook in OneNote Online (at www.onenote.com). This
can help determine if the problem is caused by the server or by OneNote.
For more details on how to fix sync issues in OneNote for Android, you can visit this
article.
Please respond to this thread to let me know how the issue progresses. Similarly, if you have more questions, please inform me by replying to this post.
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