Posted by: @dimalifragis

This update crashed our site and we had to remove via ftp our caching plugin (Comet Cache).

[18-Dec-2020 19:17:41 UTC] PHP Fatal error: Uncaught Error: Call to a member function get_page_permastruct() on null in /home/wp-includes/link-template.php:375

Your problem is not related to this update. Please read this FAQ topic and update again: https://wpforo.com/community/wpforo-integration/fatal-error-server-error-503/

@dimalifragis,

Try to find the full error message. The line you've posted here says nothing.

@dimalifragis,

Don't forget to exclud forum page from your new cache plugin. Here is the description: https://wpforo.com/community/faq/wpforo-and-cache-plugins/

@maschinist,

The cache plugin you're using hasn't been updated 2 years. The conflict with a plugin was just a matter of time. wpForo just calls the wp_clean_post_cache() and the outdated plugin hooks to this WordPress core function and generates fatal error. If you have such a large site you should periodically che the plugin and make sure they are  tested and updated for the latest WordPress major releases to avoid such problems and conflicts with other plugins. This cache plugin has not been tested with the latest 3 major releases of WordPress: