Hello
I'm trying some Facebook comment plugin into my J! 2.5.14 site with K2 2.6.7 but Comment box alway appear into K2 video box (www.antoniocornacchia.com/diario/giorno-per-giorno/item/292-la-marca,-il-marchio,-la-ruota-della-fortuna-e-renzi.html) and change template settings (text is bigger than without plugin www.antoniocornacchia.com/diario/giorno-per-giorno.html).

I get this with more than one plugin, so I suppose it is not a plugin related issue.
How can I fix it?

Hello,

You are right this is a template issue, not a plugin issue. Open your template's item.php go to the video block and check if there is a plugin event code in there and delete it.

I would ask the template developer as well if that plugin event is needed elsewhere.

It is the K2 default template

<!-- Item video -->
<a name="itemVideoAnchor" id="itemVideoAnchor"></a>

<div class="itemVideoBlock">
<h3><?php echo JText::_('K2_MEDIA'); ?></h3>

<?php if($this->item->videoType=='embedded'): ?>
<div class="itemVideoEmbedded">
<?php echo $this->item->video; ?>
</div>
<?php else: ?>
<span class="itemVideo"><?php echo $this->item->video; ?></span>
<?php endif; ?>

<?php if($this->item->params->get('itemVideoCaption') && !empty($this->item->video_caption)): ?>
<span class="itemVideoCaption"><?php echo $this->item->video_caption; ?></span>
<?php endif; ?>

<?php if($this->item->params->get('itemVideoCredits') && !empty($this->item->video_credits)): ?>
<span class="itemVideoCredits"><?php echo $this->item->video_credits; ?></span>
<?php endif; ?>

<div class="clr"></div>
</div>
<?php endif; ?>

The code seems fine. RC sometimes puts their overrides in the /components/com_k2/.. folders so you might want to check that files also.

In your position if the commenting plugin does not offer any settings I would comment out plugin events in your template.

I solved without using any plugin and inserting the original Facebook code into item.php manually.
Regards