404 error when trying to open the editor beaver builder (Free version )

Hi and sorry for bad English.
I am using WordPress beaver builder (Free version ) for this website: https://wcblogs.com/
But today, I am having issues, when I edit or publish a new post or page, the website shows, 404 error when trying to open the editor.

I removed all browser cache and i deactivate the WordPress caching plugin. so someone please suggest me, what should I do now?

Thanks