I have used SREP on several Real Estate sites and they are working great. I haven't upgraded those sites to 3.9.x yet. I am building a new Real Estate site on a clean install of 3.9.1 and everything works except the Yelp shortcode. The shortcode
[yelp lat="35.6256411" lng="-120.68848359999998" radius="3" sortby="distance" term="restaurants"] displays a blank screen.