If the filename or the path contains the ")" character, the image doesn't show because the thumb element have the style attribute as this:
<a href="... " style="background-image: url(http://mydomain.com/path/filenamewith).jpg)" ...
This could be resolved adding the ' delimiter before and after the image path:
<a href="... " style="background-image: url('http://mydomain.com/path/filenamewith).jpg')" ...
So you can modify the row 36 with this:
$(this).parents('.sp-wrap').find('.sp-thumbs').append('<a href="' + large + '" style="background-image:url(\'' + thumb + '\')"'+classes+'>');
If the filename or the path contains the ")" character, the image doesn't show because the thumb element have the style attribute as this: <a href="... " style="background-image: url(http://mydomain.com/path/filenamewith).jpg)" ...
This could be resolved adding the ' delimiter before and after the image path: <a href="... " style="background-image: url('http://mydomain.com/path/filenamewith).jpg')" ...
So you can modify the row 36 with this: $(this).parents('.sp-wrap').find('.sp-thumbs').append('<a href="' + large + '" style="background-image:url(\'' + thumb + '\')"'+classes+'>');
Hope it helps.