Additional info:
class.timeline-express.php / line 1049:
<<?php echo $title_wrap; ?> class="cd-timeline-title"><?php if ( $this->timeline_express_optionVal['timeline-title'] != '' ) { echo apply_filters( 'the_title' , $this->timeline_express_optionVal['timeline-title'] ); } ?></<?php echo $title_wrap; ?>>
The title_wrap variable is empty when no title is set in the backend.
I ran into this today as well – it seems to happen when you have no title configured in the admin. Once you add a title the element gets rendered properly.