When I click on "amd64" to download FreeBSD amd64 v. 10.2, the link I get is: "ftp://ftp.freebsd.org/pub/FreeBSD/releases/amd64/amd64/ISO-IMAGES/10.2/". With Mozilla Firefox this link produce a blank page. So I searched on Google a page to download FreeBSD, and I get this link: "http://ftp.freebsd.org/pub/FreeBSD/releases/ISO-IMAGES/10.2/" This link works well. So, probably you have to change the links on the download page. Sorry for my English, but I am Italian.
The link works for me with Firefox 41.0.2 on FreeBSD and Firefox 42.0 on Arch Linux. What version of Firefox do you use?