As an added note, you may also find the
Can't DCC Send thread (for when you're sending) helpful, and
this page for some common issues when receiving a file.
If you have received in the past but can't now, and the above suggestions don't work, then the chances are it's the sender's problem. It usually is in a transfer, as you need to connect to THEM in order to get the file, therefore, if they have ports blocked a connection may not be possible so the DCC fails.
Try sending your friend that's sending you the file to the 'Can't DCC Send' thread and see if those suggestions help him.
Regards,
