Hi Rob,

This is a hard question because we will never know all the details here. But try the following to see if that will sync. Creat a new clean Notebook. Now go back to your Old notebook that does not want to sync. Now right click the first section (tab) and choose Move or Copy. Now browse to the 'new' notebook and click ok. But be sure to choose copy and not move. Now sync the new note book from the other location. If it works copy all sections from your old notebook this way to your new notebook.