I could reproduce exactly the same the problem with Firefox 43, but only with Adblock Plus enabled. (True, nothing happens if you press Continue.) If I disable Adblock Plus - not even restarting Firefox is required, just reload the page -, the ad gets displayed, I skip it and download the file.
(Funnily enough, I also chose the page of DOOM [2016] for testing, even before looking at your screenshot.
)
Could you try an
older version of Firefox? Perhaps, newer Firefoxes themselves block some pages (malware blacklist?), even without the help of Adblock Plus. Also, create a new Firefox profile, with default settings, and try again; if you can download files then it's something in your current settings that blocks this page.
[...] Actually, I could download files with Opera 12.18 and
very restricted default settings, eased off for these particular sites. It may be cookies being blocked...