Figured out why firefox was not loading http images on a https website.
7 months ago I created a custom user file which applies more security rules for firefox than any of you guys would even dream about and while doing so I enabled security.mixed_content.block_display_content. This does exactly what it says it does, blocks display content (images in this case) from loading if you are loading http content from a https website. This was to prevent attacks where a man-in-the-middle could tamper with the non encrypted http data and give you data that was not meant to be. For example if an https website was loading an iFrame from a non https website, I could hijack the request and change the content of the non https request and insert malicious code or content into it. Mean while the user thinks they are safe because they are browsing an https website.
Anyways if anyone is interested they can drop this into their profile and name it "user.js",
https://raw.githubusercontent.com/pyllyukko/user.js/master/user.jsMake sure to go through it line by line because it heavily modifies firefox for security which may be an annoyance. Such as it deletes all cookies, sessions, history, and the like when you close firefox. It automatically starts in private browsing mode no matter what. And it disables referers/mixed content loading and the like. Some of which you may want to enable or disable. Meanwhile it also adds a bunch of security features like blocking page precaching, disabling firefox telemetry, disabling ways to probe/identify your system through your browser, and locks down weak encryption used for HTTPS so that only strong encryption is used.
This post was edited by AbDuCt on Jun 5 2016 10:21am