Like Jason above, I have tried everything I can think of to get the (unsupported) Microsoft OneNote importer to work and had no success. I finally have had some success using another tool mentioned in another thread - Stefans Tools Evernote2Onenote utility (Evernote2Onenote - Stefans Tools (stefankueng.com)). It does have some significant limitations, especially regarding notes with multiple tags - read the release notes carefully. I was able to get this to work by installing the OneNote desktop app (aka OneNote 2016, not the OneNote for Windows app) and the legacy Evernote app. When you run the Evernote2Onenote utility you may get a message "Could not find the ENScript.exe file" and will need to manually select this in the next dialog box. For me, this file was found in the C:Program Files (x86)/Evernote/Evernote Legacy directory. I was able to import my Evernote notebooks successfully using this utility, however I do have a lot of cleanup work to do to remove the duplicate notes due to the multiple tag limitation (I do not want to mess with my Evernote structure if I later decide OneNote isn't going to cut it for me).
Jason, this might be worth a shot for you, your mileage may vary.
--Doug