Your question prompted me to look at my own OneNote setup. I confess that I can't see the point of indexing OneNote when X1 cannot preview OneNote data. But I managed to get X1 to index on OneNote files.
I did have to ensure that X1 was looking in the right places. Like many things Microsoft, the software seems to know better than I do where to put its data. I like putting things where I can easily manage a backup regime. Ity turns out that I have OneNote things scattered around my PC.
As one of the ideas behind OneNote is to put things in the cloud, and on OneDrive, X1's inability to handle that is also a hindrance. (I assume that the decision to index Box cloud storage was down to customer demand rather than any kickbacks from Box, which seems to be the least used cloud service going, after OneDrive, Google, DropBox and so on.) So, I have to ensure that stuff is in the right place.
I did have to ensure that X1 was looking in the right places. Like many things Microsoft, the software seems to know better than I do where to put its data. I like putting things where I can easily manage a backup regime. Ity turns out that I have OneNote things scattered around my PC.
As one of the ideas behind OneNote is to put things in the cloud, and on OneDrive, X1's inability to handle that is also a hindrance. (I assume that the decision to index Box cloud storage was down to customer demand rather than any kickbacks from Box, which seems to be the least used cloud service going, after OneDrive, Google, DropBox and so on.) So, I have to ensure that stuff is in the right place.