A reader just alerted me to a serious bug in Evernote effecting Mac users.

We have identified a bug in some versions of Evernote for Mac that can cause images and other attachments to be deleted from a note under specific conditions. We've released an updated version of Evernote for Mac, version 6.9.1, to resolve this. Please open Evernote and navigate to Evernote > Check for updates… to get this latest version. If you are using the Mac App Store version of Evernote, this new release has been submitted for approval with Apple, and is estimated at being available for download from the App Store next week.

More comments in the Evernote forum