[Gautam]

This shouldn’t be the case. However, check the topic.php of your theme and see if there is the currect loop. It should look like this:

<?php foreach ($posts as $bb_post) : $del_class = post_del_class(); ?>

<li id="post-<?php post_id(); ?>"<?php alt_class('post', $del_class); ?>>

<?php bb_post_template(); ?>

</li>

<?php endforeach; ?>

And did you follow the steps to upgrade written here – https://bbpress.org/documentation/upgrading/