Modules are not showing up for editing on the page

I have created a landing page using beaver builder. I want to make some adjustments to the page. After pages loaded, I can not do anything. The modules are not loading even not showing up.
The navigation menu appears too big. (please see attached file). Altogether there are 13 landing pages but the error appears only 3 landing pages and the rest of the pages working fine.
I spent more than a day solving the problem but I do not have any idea why this error appears. Your valuable help is much appreciated.