I have the same/similar problem. HOW CAN YOU EASILY SAVE A PDF OPENED IN PREVIEW TO EVERNOTE, AND HAVE THE RESULTING PDF IN EVERNOTE NOT BE CORRUPTED?
This is how I am saving from Apple Preview to Evernote: PDF open in Preview can be "shared" to Evernote using the SHARE button --> dropdown menu --> Evernote button. Flipping over to Evernote, the note is successfully generated. However, the pdf attachment won't open, says it's a pdf and that it might be a damaged file.