Typo3 error message at Flexible Content - Download Links

Question

what does this error message mean in backend:

Ordner mit Dateien zum Download (geschützte Dateien müssen in einem Unterordner 'protected' sein!)

I moved the original to my development and the pictures are now not showing in frontend.

Thank you!

EDIT:

Here are images from Backend:

Answer 1

This is a label of a field which is displayed in the page view. There is no error message.