The credentials you provided above does not work, so I was not able to look at the backend.
But I saw this, that is strange because those files are critical to the Theme and your site is not giving/loading it.
Did a failed update happen on your site recently?
Please re-install your X THEME, but follow the Manual X Update Via FTP guide provided here, this is to make sure that your X THEME is clean and all files needed exist.
Remember to clear all caches (plugin, server-side, CDN, and browser's cache) after updating so that the code from the latest release is always in use. This will help you to avoid any potential errors.
Let us know how it goes,