Some thumbnails not generating correction

I have a wordpress site I am rebranding. Starting from scratch. I have everything working pretty much perfectly. Site is even responsive. When I imported the data from the old site to the new site though I am suddenly getting a lot of thumbnails that are not generating the code properly.

Here is the URL: yhponline.com

Also here is a sample of the html being generated where you can clearly see that not all of the thumbnail posts are even generating img tags.

<article id="post-17450" class='post_right'>
      <div class="thumbnail">
        <a href="https://yhponline.com/2013/03/07/nick-green-printed/"
title="Interview: Nick Green and printed want to make your life easier ordering printed materials" ><img width="140" height="140" src="https://yhponline.com/wp-content/uploads/2013/01/Nina-Devani-Prompt-me-Nina-150x150.jpg" class="attachment-160x140 wp-post-image" alt="Nina Devani, Prompt me Nina" 0="" /></a>
      </div>
      <div class="post_content">
        <h2 class="entry-title"><a href="https://yhponline.com/2013/03/07/nick-green-printed/" title="Interview: Nick Green and printed want to make your life easier ordering printed materials" rel="bookmark">
          Interview: Nick Green and printed want to make your life easier ordering printed materials          </a> </h2>
        <div class="entry-content"> I invited Nick Green on YHP to share his story on his journey so far especially since starting printed.com.

Hi Nick, Thanks for doing this. How are you doing today?

Great thanks! Amongst other thi <a href="https://yhponline.com/2013/03/07/nick-green-printed/" class="read_more" title="Interview: Nick Green and printed want to make your life easier ordering printed materials" rel="bookmark">Read More...</a> </div>
      </div>
    </article>
        <article id="post-17452" class='post_left'>
      <div class="thumbnail">
        <a href="https://yhponline.com/2013/03/07/sergey-kuznetsov-vcv/" title="Interview: Sergey Kuznetsov, VCV.RU" ></a>
      </div>
      <div class="post_content">
        <h2 class="entry-title"><a href="https://yhponline.com/2013/03/07/sergey-kuznetsov-vcv/" title="Interview: Sergey Kuznetsov, VCV.RU" rel="bookmark">
          Interview: Sergey Kuznetsov, VCV.RU          </a> </h2>
        <div class="entry-content"> I invite Sergey Kuznetsov onto YHP to share with us his expedition towards starting VCV.RU and in general, his entrepreneurial journey.

VCV.RU is an online service for the quality search of candidate <a href="https://yhponline.com/2013/03/07/sergey-kuznetsov-vcv/" class="read_more" title="Interview: Sergey Kuznetsov, VCV.RU" rel="bookmark">Read More...</a> </div>
      </div>
    </article>