Hi,
You are referring to ‘posts’, so maybe you mean standard WordPress blog posts ? In that case you better ask the question on https://wordpress.org/support/
If you mean bbPress ‘Topics’ or ‘Replies’, then your admin panel should only show you some topics or replies at a time, so you should be able to see them under the corresponding headers in your menu and delete them.
Topics and Replies are stored in the database as standard posts, so they should be there.
@casiepa sorry, of course I meant “replies”. Actually I have 500 replies (many of them are deleted because they’re not visible on forums), and when I try to see the Replies page in Admin Panel, I get error 500. I checked wp_posts records and they’re no forum replies.
I altered wp-mass delete to allow bbpress options
WP Mass delete bbpress version
USE WITH CARE and backup your database first !!! I take no responsibility for this !
@robin-w am I able to choose which posts I can save and which to delete in your plugin settings?
I just added bbpress options to the wp-mass delete plugin. If you install it you can see what settings it has and whether it will suit you