Have bbPress on a WordPress site - Forums and Topics work just fine on the frontend and backend. However, Replies totally crash the site – on the front-end, they just fail quietly, but Add New on the Replies page in admin causes WordPress to fail. Copying over the first 100 lines or so of the stack trace to see if it helps any with what could be causing it. Error: Xdebug has detected a possible infinite loop, and aborted your script with a stack depth of '1024' frames at /www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-object-cache.php:141 at WP_Object_Cache->is_valid_key() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-object-cache.php:364) at WP_Object_Cache->get() (/www/kinsta/public/internationalmidwivesorg/wp-includes/cache.php:154) at wp_cache_get() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-post.php:240) at WP_Post::get_instance() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post.php:1036) at get_post() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post.php:1495) at get_post_type() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/common/template.php:454) at bbp_is_reply() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:544) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) at bbp_get_reply_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:549) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) at bbp_get_reply_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:549) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) at bbp_get_reply_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:549) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) at bbp_get_reply_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:549) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) at bbp_get_reply_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:549) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) at bbp_get_reply_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:549) at bbp_get_reply_title_fallback() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:324) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/post-template.php:174) at get_the_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/topics/template.php:603) at bbp_get_topic_title() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/bbpress/includes/replies/template.php:1405) Have attempted to turn off other plugins, turn off and turn back on bbPress, etc. When The Events Calendar plugin is activated, the stack trace is slightly different - still throwing a possible infinite loop, but in totally different places. The first few lines of that stack trace are below. Error: Xdebug has detected a possible infinite loop, and aborted your script with a stack depth of '1024' frames at /www/kinsta/public/internationalmidwivesorg/wp-content/plugins/the-events-calendar/common/vendor/vendor-prefixed/lucatume/di52/src/Builders/Resolver.php:315 at TEC\Common\lucatume\DI52\Builders\Resolver->getBuildLine() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/the-events-calendar/common/vendor/vendor-prefixed/lucatume/di52/src/Container.php:248) at TEC\Common\lucatume\DI52\Container->castThrown() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/the-events-calendar/common/vendor/vendor-prefixed/lucatume/di52/src/Container.php:222) at TEC\Common\lucatume\DI52\Container->get() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/the-events-calendar/common/src/Common/Contracts/Container.php:24) at TEC\Common\Contracts\Container->get() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/the-events-calendar/common/vendor/vendor-prefixed/lucatume/di52/src/Container.php:271) at TEC\Common\lucatume\DI52\Container->make() (/www/kinsta/public/internationalmidwivesorg/wp-content/plugins/events-calendar-pro/src/Events_Pro/Custom_Tables/V1/WP_Query/Provider.php:391) at TEC\Events_Pro\Custom_Tables\V1\WP_Query\Provider->hydrate_cache_on_occurrence() (/www/kinsta/public/internationalmidwivesorg/wp-includes/class-wp-hook.php:326) at WP_Hook->apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/plugin.php:205) at apply_filters() (/www/kinsta/public/internationalmidwivesorg/wp-includes/meta.php:635)