On other pages on permies, chrome says "secure". Somebody reported this page as their browser freaking out about it being "insecure". So I think there is an image on that page that is loaded with "http" instead of "https".
Is there a plugin or maybe a web page somewhere (where you plug in a url) and it can tell you what bit of a page is the problem?
The page has a mix of secure (https:) and unsecure (http:) links on it. Note the missing "s" in the unsecure links
About 1/3 of the links to other parts of permies.com on that page is an unsecure http: link that then gets redirected to https: after you click on it.
There are nearly 300 unsecure links on that page. Chrome doesn't complain about them, but other browsers might.
If you'd fix your code that generates your pages to only point to https: links, that might fix the problem, it would at least make it easier to track down.
On that particular page, a script belonging to google is generating http:// thumbnails for the videos.
I can check that, by waiting a long, long time for the page to load, and then selecting "Tools -> Page Info -> Media" using the current version of FireFox web browser. Yes. I still use a menu, those that don't can get to "page Info" by right clicking on the background of the page.
I don't know what this is, but I was right clicking stuff and it says "view page source" or something like that. I clicked it for this page and it looked like html with all the pointy brackets and stuff. I did a contrlF (find on page) and searched "http:" and it found 111 instances of that on the page.