The File attributes block is screening the contents of the parent folder, with the option to do filtering ("include Subfolder names") on the target folder, which we suspect is empty.
The output will contain some data, regardless of the contents of the folder X.
When we use a Record filter on the field [Enclosing folder] we can output the contents of the folder X and pass it to the Validate data block to decide whether this outcome should be passed on, or stopped by an Error action. (Record count validation criteria Max records is set to = 0)
This 'empty dataset' is then appended with some content and passed on for further processing.