Fix OneNote Notebook Sync Errors Due to 2GB Size Limit on OneDrive

Open OneNote and click on 'File' > 'New'. Choose 'OneDrive' as the location, give the new notebook a relevant name, and click 'Create Notebook'.

Navigate back to your oversized notebook. Right-click on a section tab that you want to transfer and select 'Move or Copy' from the context menu.

In the dialog box that appears, select the newly created notebook as your destination and click the 'Move' button. Do not use 'Copy', as copying will not reduce the original notebook's size.

Repeat the moving process until the original notebook is significantly smaller. Then, right-click the original notebook's name in the sidebar and select 'Sync This Notebook Now' to ensure the error is cleared.

Browse through the pages of your oversized OneNote notebook to find large inserted files, such as PDFs, PowerPoint presentations, or video clips.

Right-click the heavy attachment and select 'Delete'. If the information is essential, consider uploading the file directly to OneDrive and pasting a sharing link into OneNote instead of embedding the file itself.

If your notes contain many high-resolution photos, save them to your computer, resize or compress them using an image editor, and re-insert the smaller versions back into your notes.