I used to be able to download from Mega on Firefox (on Macbook Pro), but a little while ago it started asked for a decryption key when there is no password needed. I just tried something tonight, and same problem.

Any ideas?

decryption key asking from bad copied link. in link it is showing as from second ! to end (format url like this "mega.co.nz/![file id]![encryption key]")

Thanks Zeratual13 for the advice. Simple when you know how. I've now got it working again.