As of 2019-10-24 14:29 UTC:
The page https://downloads.jabref.org/ (referred to by the link anchored on the release number — as of now: “release: v4.3.1” — to the right of the “JabRef” title at the beginning of the content of the JabRef home page https://www.jabref.org ) fails to redirect, and instead just displays the text:
This page redirects to the current download provider of JabRef.
The implementation follows a tutorial by W3C.
Issue tested/verified with the browsers:
Firefox, Safari, Brave under macOS, and Firefox and Chromium under Ubuntu/Linux.
(due apologies if this should be a duplicate)