Whenever I or one of my forum users wants to start a new topic, we get the following error message:

Failed to load plugin: wpforo_spoiler_button from url https://nextlevelfreelancer.com/wp-includes/js/tinymce/plugins/wpforo_spoiler_button/plugin.min.js

I've had a look around on the forum, saw one person with a similar problem however I did not find a fix for the problem in that thread.

any tips to resolve this problem?