Also getting the "Failed to Export Notes" message.
I am running Evernote desktop client on Windows and exporting by right clicking the name of the notebook in order to include all 7,000+ notes as an ENEX. I'll get 24%-29% through the export before the error is generated.
I realize it's alot of notes for one export (and some have attachments), but that's what happens when you use program for a few years.
Any approaches that have worked?