Argh, in the same boat here. I tired the solution. I duplicated the note. The new note has the same problem right out of the gate. I can't copy the content in order to paste it into a new note either. And it's one of my most frequently used notes, so I bump into it multiple times a day. The note was wholly created and edited in Evernote and I have never used a different app to edit it, and never even pasted content into it from another app. Everything has been typed natively in Evernote.