I haven't run into this error since the iOS Mail app changed back to it's previous behavior of downloading an entire email message without the user tapping at the bottom of the screen. Now it's recently started showing up when a user launched fmGo 13. Specifically, the error says "<file name> is damaged and cannot be opened. Use the desktop product's Recover command to recover this file". The super strange thing is sometimes, one can swipe-quit fmGo and then come back in and it functions normally. What can cause this error to come up?