DJS-TSP Project Creator - No manual and drag drop samples doesn't work

How on earth does anybody use DJS-TSP Project Creator to get samples into projects for export to a USB stick?

Pioneer's web site says there is no manual for this software which is ridiculous when the software is so unintuitve and difficult to use.  In fact other sites show what looks like an official manual but you either have to hand over money or sit and watch a long ad on EVERY SINGLE PAGE before you can read it. Why can't Pioneer just supply the damned thing on their downloads page?

I found a YouTube video that showed the DJ just dragging samples onto the pads in a new project in the software.  When I try this on my Windows 10 machine the pad displays the usual + cursor over the pad indicating the sample will be added, but then nothing happens and the pad remains blank.  I am just dragging standard .wav samples across.

How am I supposed to get samples into this software so I can then export a project to a USB key, and does anybody have a download link for the missing manual?