Events+ my template doesn't work in Firefox

I have a template in use for [eab_archive] that works just fine in Chrome, but in Firefox, it's just giving me a blank page.

The template is this:

<?php
// template used to display  shortcode lists e.g., [eab_archive template="event-list-with-thumbnails"] also works with [eab_expired] //
?>

<?php
if ($events) {

        foreach ($events as $event) {

        ?>
                <section class="eab-events-archive <?php esc_attr_e($args['class']); ?>">

                <?php $event = $event instanceof Eab_EventModel ? $event : new Eab_EventModel($event); ?>
                <article class="eab-event <?php echo eab_call_template('get_status_class', $event); ?>" id="eab-event-<?php echo $event->get_id(); ?>">
<div class="event-listing">

                                <span class="event-listing-thumbnail"><?php echo $event->get_featured_image(); ?></span>

                <span class="event-listing-title"><?php echo $event->get_title(); ?></span>
                                <span class="event-listing-meta"><?php echo eab_call_template('get_archive_content', $event); ?></span>

                                <span class="event-listing-excerpt"><?php echo $event->get_excerpt_or_fallback(300); ?></span>
</div>
                </article>
                </section>

        <?php }

        } else {

                        //do nothing
        }
?>

The page where you can see it's not working is

http://beta.nrocnetwork.org/resources/upcoming-webinars/

If I take the template argument out of the shortcode (to use the default instead) then the page displays two upcoming events.

Any idea what's wrong with my template? (or what's wrong with Firefox....)