I've problem when "Image Source" is "Category" and "Grab Post Image&am

i select “Image Source” = “Category” and “Grab Post Image” = “First” and then first image at last post view in slider but doesn’t slide images.
But when i select “Featured” for “Grab Post Image” all thing is right;
Thus I solve this problem by change line:1037 in vslider.php

This code:

<div style="background: url(<?php echo $img_url; ?>) no-repeat;<?php echo "width:" . $options['width'] . "px; height:" . $options['height'] . "px;"; ?>" alt=""></div>

Should replace with:

<img src="<?php echo $img_url; ?>" alt="" />

thanks for this brilliant plugin ??

https://www.ads-software.com/extend/plugins/vslider/