I figured it out. After exporting the notes, Evernote is displaying a message saying that my exported notes were placed in a file (and it gives the file name). I thought that this meant Evernote was finished exporting the notes, but apparently it does not mean that. As I discovered today, the file size continues to grow as the file is continuing to be created in the background. I was trying to then use/import/view these files too early. After waiting until the enex file was actually finished (the date/time modified would update) then the file created was fine.
