"Broken links in CSS styles" error reported in WebCEO

https://www.crownmountainguides.com/
I am trying to address a “Broken links in CSS styles” error reported in WebCEO - https://www.crownmountainguides.com/media/emptystate.85a4add5.svg broken in CSS on 5 of the site’s main pages.

It has something to do with the Pro Gallery. How can that be fixed?