Please delete all caches, delete hosting cahe if you have, then purge CDN and JS/CC minify caches.

You have JavaScript error on your website. This screenshot says the editor is crashed because of JS error. It comes from recent theme update or from other plugins. Also this kind of error comes from optiizer / minifier  plugins. Please leave your forum URL to allow us check JS errors.

I am not using any 3rd party caching plugin on the forums.  I have disabled for the forum directory.  

I deleted the cache within the forums.  

However, I am still having problems.