The discussion revolves around a bug where Livestream mixed content warnings prevent Onebox from rendering on Discourse. jqnatividad reported the issue, noting that Onebox renders in preview but not after posting. eviltrout identified the problem as Livestream not supporting HTTPS, causing mixed content warnings.
jqnatividad sought workarounds, but eviltrout initially believed it wasn’t possible to fix without Livestream adding HTTPS support. However, DeanMarkTaylor pointed out that Livestream does support HTTPS, but their canonical redirects are broken.
eviltrout subsequently added support for Livestream via forced HTTPS to onebox in master, which should resolve the issue for most users, although the poster may briefly see a mixed content warning.
It looks like livestream doesn’t support HTTPS? When I change that URL to HTTPS it just redirects back. So if you are using HTTPS on a discourse, you will get a mixed content warning.
^^^ It looks like the preview image gives a mixed content warning but once the video is rendered it goes away. That should be OK for most people as only the poster will see the warning briefly.