/wp-content/plugins/bbpress/includes/admin/classes/class-bbp-converter-db.php
I commented out lines 33-37:
// register_shutdown_function( array( $this, '__destruct' ) );
//
// if ( WP_DEBUG && WP_DEBUG_DISPLAY ) {
// $this->show_errors();
// }
I started getting this error after I upgraded to PHP 8.1. It prevents login, so this is a problematic error. BBPress is trying to setup a new login object and in the process wants to destroy any existing login object. Because BBPress doesn’t actually have a __destruct method php8.1 throws an error. I commented out that block of code and everything seems to work correctly. Of course that is a temporary fix that will be overwritten as soon as the plugin is updated.
I don’t have Jetpack installed on this server so it is not the culprit.