In link details page there are six fields, the "comment" one reports the real link JD is downloading.
If some external error occurs (server error, etc), it could be very useful to copy the link to open it in browser (in most cases it works, also to re-register in JD)
Well copying is really hard, 'cause the text stands selected (to be copy-able in clipboard) just a nanosecond, while other fields stand selected for centuries of centuries.
I couldn't find any setting about this behaviour nor any discussion...
I've screen captures available if they could be useful.
Thanks in advance.

[Jiaz]

we will fix this with next major update, as this dialog will change in future versions too

@giorcon1977

If you want to copy the link that's downloading, then just select the link in the Download tab and select "Copy URL" in the context menu.