I let Evernote (5.something, pretty recent) on my 10.9.5 box upgrade itself to version 6.0. None of my messages are available. Actually, sometimes they appear when I click their title, but then the text disappears when I click another note. I checked the web GUI, and the notes are still there (whew!) I read about some other bugs in 6.0, so I manually downloaded 6.0.1 from the website. Result: - I seem to have all my notes. - I seem to have lost all the note titles from the few items I attempted to open. I was able to re-type them in the OSX client After a few minutes of further operation, it seems to be working OK. Still, pretty crummy upgrade.