Hi @mohammad_alqoqa , unfortunately as you have discovered it looks like those videos aren’t available any longer which is unfortunate but if I recall they were just demonstrating what the drag and drop problem looked like.
I did post a screenshot recently describing dragging and dropping a component from the hub which may be useful though…
Might I suggest you take a look directly at this comment on the earlier thread I mentioned…
… and try performing the temp installation using a zip download and see if drag and drop works on that installation.