In other words: replacing this
Code:
<meta content="2016/05/19" name="dcterms.date.of.publication">
Code:
<meta content="2016-05-19" name="dcterms.date.publication"/>
And then reimporting that into a new ebook should fix at least that first error message.
But again, it would probably be best to use the GUI Metadata Editor tool to fix thigs there which is the only place either FlightCrew or epubcheck will look to see if things are correct.
Still not sure what the second error message is about. Can you go to the content.opf Tab and copy the metadata section and paste it here. That should help me to see what is going wrong.
KevinH