Facebook share does not show image

This is whether the link is pasted into a Facebook post or shared from the page icon, or from the browser menu.

All other themes work fine.

The Facebook sharing debugger has this error:

Invalid URL
Provided og:image URL, was not a valid URL.

for this URL:
https://bernproject.com/blog/2016/06/29/what-bernieorbust-movement-means-to-me/

And all of the other URLs on the site.

The home page however, has a different error:

Share App ID Missing
The ‘fb:app_id’ property should be explicitly provided, Specify the app ID so that stories shared to Facebook will be properly attributed to the app. Alternatively, app_id can be set in url when open the share dialog.