Strange error message on Layerslider WP -> Transition Builder

Nope. The files are not corrupt. You are misguiding him with your advice to re-download the entire package. The javascript files are simply not there, or for some highly odd reason, they vaporize in thin air from the inside of a zip file upon download. They simply don’t exist in the folder. Go look for yourself. The PHP error message in his screenshot tell you the story and exactly where to look. It will take you a few seconds with a wildcard *.js search on your local computer to confirm this. We have the same PHP error messages here with three downloads from two different versions of Enfold. I would suggest you also look for other missing javascript files too. Because there’s more than one that’s missing in action.

When you replace the missing files, it sure would be good to give an announcement to your customer base in some fashion. Fortunately, the javascript files are not major features to the slider plugin and don’t affect the entire theme much. It still works, but lacks customization in areas and some of the buttons don’t fire the appropriate javascript functions due to the missing scripts.