invalid meta markup

I have some invalid meta markup showing up on my pages where customers download my products. It seems to be a <span> issue inside the <meta name>.

You can see the example here: http://debistangeland.com/downloads/31-days-prep-course-workbook/

There is a white box at the top of the page with the title.

The code looks like this:

<meta name=”twitter:title” content=”<span itemprop=”name”>31-Days Prep Course Workbook</span>” />

See that <span> property? How do I get rid of that?

Thanks!!

https://wordpress.org/plugins/twitter-cards-meta/