I support http://lifering.org, a single site installation of WordPress 4.0.1. We recently decided it would be a good thing if we could force the entire site to https. (LifeRing is a drug-and-alcohol recovery group, so site discussions tend to be very personal.) We have an SSL certificate.
Our test site is at https:\lifering.org\sitetest.
The test site seems to be https. But on certain pages, if you press F12 in Chrome or use some other tool to look at the console, you'll see a scatter of error messages of the "this is loading as http and should be https" errors, mostly for images and xml files. Some of these files are in links I can't even find in the page code.
I particularly see the non-https errors on this page: https:\lifering.org\sitetest\chat-room.
We use this page for the local portal of our chat room, hosted by 123FlashChat. We've followed 123FlashChat's instructions on how to make it https, but we still see indicators that it isn't secure. How serious is it to have non-http links for something like GIFs and JPGs? I have no experience with this. And, how do I fix a link error that I can't even find on the page?