This is a meta-topic. This forum sources some fonts from Google but through HTTP. Please switch to HTTPS.
WFM in FF 67 win64. This is the list of requests made for the current page:
https://travis-ci.community/t/mixed-content-in-this-forum/3645
https://travis-ci.community/message-bus/8897831fab784db692bafcfac4b5fce7/poll
https://sea1.discourse-cdn.com/flex015/brotli_asset/locales/en_US-bef12b1ff2a2a2566ed25df5d9500fd2975d7259d2a11b7ee1f025b8e9f1d977.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/ember_jquery-0ae86c6a7527a99c2b9b8a11521273bd9cb4f7d41bc546df081b7ee94f26d9c3.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/preload-store-081120a9f8cb0871483b66a95e534ce8e81f97d19c8cef978aea6c696d1feb20.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/vendor-25f91d66eba869fbd399d751711e74544b6d60bf034a5350b61c6c12caad0e2a.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/pretty-text-bundle-9aba731d6eceda3d220e39cce1bf725449321c4803b7601b71a5dc925f148c22.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/application-7e90d098ca29ed6222a1c89d26afd5e076c02e640108d024f2ab8de030da3a71.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/plugin-372fc0ae6bd5effd06a9bc4eb67737e73f4c20be111e26bda6c10ba2b04c7be0.js
https://sea1.discourse-cdn.com/flex015/brotli_asset/plugin-third-party-4db9f7e6b94b96b458fae77cf286250fc99833f675904173cf7bcd3288b07583.js
https://sea1.discourse-cdn.com/flex015/stylesheets/desktop_31d7d2f8e22a6d207e69abfefcca4a7ced533d4e.css?__ws=travis-ci.community
https://sea1.discourse-cdn.com/flex015/stylesheets/desktop_theme_2_2f4a4ea7191cde54b7db83d1cdd4b9ce55d3b6a4.css?__ws=travis-ci.community
https://sea1.discourse-cdn.com/flex015/brotli_asset/preload-application-data-0a59ccab480941aaac91f9e7fa7f77496323ae056aaa4158822dea35de319c01.js
https://fonts.googleapis.com/css?family=Open+Sans
https://sea1.discourse-cdn.com/flex015/brotli_asset/browser-update-1741a2ed67a367faeb0a582af064457e8b1b1354e52e6efcf8bf26301166dec8.js
https://sea1.discourse-cdn.com/flex015/uploads/travis_ci/optimized/1X/1cc38c213e0a8e87e2d3430ba84aa0f6a03c61b0_2_180x180.png
https://sea1.discourse-cdn.com/flex015/uploads/travis_ci/optimized/1X/0f5ecc78b2da2e231c521a5d53cc48aa12f91f36_2_32x32.png
https://sea1.discourse-cdn.com/flex015/svg-sprite/travis-ci.community/svg-2-bcff4c9411a736ef3f8e1f6dbf2ef9766eea914f.js
https://sea1.discourse-cdn.com/flex015/javascripts/jquery.magnific-popup.min.js
https://global.discourse-cdn.com/flex015/uploads/travis_ci/original/1X/e8f4998fa50cfd83f42adedbde4b9cca3c80e168.png
https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/native-api/32/430_2.png
https://sea1.discourse-cdn.com/flex015/user_avatar/travis-ci.community/franklinyu/45/1932_2.png
https://div.show/element
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll
https://travis-ci.community/topics/timings
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll?dlp=t
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll?dlp=t
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll
https://travis-ci.community/message-bus/539bd15ebcc3426c8a45e4c633054616/poll
It seems to be related to the theme. Try dark theme.
Confirmed for the dark theme.
@dominic, the offending http:// URL is located in https://sea1.discourse-cdn.com/flex015/stylesheets/desktop_theme_1_4739facc17ec25e183cea1fab1e3992dc1581c98.css?__ws=travis-ci.community
Isn’t that a Discourse issue, then? Or do we have to tweak something?
Found it. Please try again.
Can confirm the fix. Thank you!
(You can click the tick icon below a post to mark it as a solution. That would also mark the topic resolved.)
(Edit: Oh, I see; you need to add the topic to one the forums where this feature is enabled to be able to do this. cf. Where to ask questions that are not specific to a language or environment?)