Same thing overhere! Can not drag and drop a song into Engine DJ.
Went back to a older version and no changes.
Is there any news how to fix this problem??
Mooi feestnummer! 
Found the problem !
In my case it was a defect USB HUB.
I have tried several usb sticks. Via hub, straight into laptop. Nothing worked 
Estou com o mesmo problema, versão 4.1, não consigo criar a playlist e nem excluir, não consigo arrastar as músicas, nada.
Conseguiu resolver o problema?