I have followed each of the download links for LO 5.4.1 and 5.3.6, each ends with a window that says “forbidden.” How do I download?
It looks like a problem about your operating system or browser. You should ask at a Mac OS forum.
Anyway, try downloading directly from a mirror, for example:
http://ftp.byfly.by/pub/tdf/libreoffice/stable/5.4.1/mac/x86_64/
The mirror did not work. However, when I tried the original link, something must have changed, because the download started immediately and download was successful.
Thanks for your help.