Soundcloud: Track loading error

I am pretty new to rekordbox

My problem is Soundcloud.

When I try to drag a track into my Deck I am getting an error warning:

track loading error. 

The track is loading 1/2 or 1/4 and then it raptly stops. The program shows me a piece of the track and then it is cut off. 

Here is picture from the cut of track:

idk...can somebody help me... 

My internet is working fine...

(i am using a simple ddj 400. Nothing special)