The "div class" you wrote was not present inside the php.
I modified the code as this (line 83):
<!-- Item Image--MOD no title no link-->
<div class="element-image">
<img src="<?php if(!empty($this->item->image)) echo $this->item->image; else echo JURI::root() . 'templates/jf_creativia/images/k2-without-image.jpg'; ?>" />
</div>
Anyway, thank you so much, the files I tried to modify in the last days were in a different folder!
This was the reason of my issue!