I found a workaround for this problem on Onenote 2016:
[Edit] before applying the below try this: I also found that some shapes created in older versions of onenote (and maybe even by onenote 2016) may corrupt you page. Try erasing and redrawing them if you are encountering page problems (as onenote not converting your ink to text or not recognizing some ink as handwritten text).
Lasso select all your ink and change the way onenote recognizes it from whatever it is to drawing (right click, 5th option, than select it in the submenu). Give it some time to process the action if your page has lots of ink. Than, select bits of hand written ink you want to convert, apply the same action, but assigning them as hand write (if the option is grayed out, try the above . Now, when you convert ink to text, onenote will not freeze on "onenote is processing the ink on this page" progress anymore. Hope it can help some people out there.
Share your results. It worked for me in pretty big pages with lots of drawings, shapes and hand written ink (no typed text, though, but it should work as the problem seams to be in the ink)
(Wish microsoft wouldn't discontinue the desktop version...)