I was trying to download Soundforge Studio 12. I have it sorted out. Modzilla/ Firefox was the problem. I installed and used Google Chrome to download the files.
I've run into the same problem with the PaleMoon browser (my current favorite) which requires temporarily switching over to an alternate.
FWIW, PaleMoon is very similar to the legacy Firefox, (ESR and versions prior to FF-57), in fact, most of the legacy FF add-on extensions work with PaleMoon.