Firefox recently upgraded for me and for some reason the Ark is showing as not safe - which seems to be related to images in the threads which now don't display correctly. I have to disable the alert on most pages to get them to display properly.

Any idea how to fix this?

Do you have an example thread or post that is causing the issue or is it every page you visit? A screenshot of the specific warning may help as well.

It's happening on every page.

I've attached and image of what you see in the address bar and what it leads to if you click on it.
Also attached an image of how each page formats, with the images at the side removed and everything shunted to the top. All images in the threads are full sized.

Thanks for the info. Going to get the site owner to check into it.

The forums haven't been officially converted to HTTPS yet. So, if you browse the forums using HTTPS, then things will break.

Replace HTTPS with HTTP for anything forum related until we apply the official switch to HTTPS.

The front page should function via HTTPS.

The main page loads correctly. Whenever I change the https to http in the other pages it automatically switches back to https with the warning. It needs to be disabled manually on each page.

FYI: I had a message saying the same safety error shows on Chrome and Edge.