Platform Support
Summary: Install curl and most problems disappear for all platforms.
I personally only use Elfeed on Linux, but it’s occasionally tested on Windows. Unfortunately the Windows port of Emacs is a bit too unstable for parallel feed downloads with ‘url-retrieve’, not to mention the hard-coded, 512 open descriptor limitation, so it limits itself to one feed at a time on this platform.
If you fetch HTTPS feeds without curl on any platform, it’s essential that Emacs is built with the ‘--with-gnutls’ option. Otherwise Emacs runs gnutls in an inferior process, which rarely works well.