I have had a Custom Page for my Cloudflare Basic Security Challenge for over 4 years. It worked fine. Recently, it no longer works. Although I have the ::CAPTCHA_BOX:: in the HTML file, the box does not show up. The users who have been challenged have no way of proving that they are not a Bot.
When I try to preview the Custom Page in the Cloudflare console, it gives me an error:
Custom error preview failed. Status code 500 received while fetching template from https://www.hockeydb.com/challenge.html
The page is a HTML page, and there is no reason it should be getting a 500 error. In fact, since my challenge page is rarely requested, I can see the request by what is likely Cloudflare in my server logs, and my logs say that the page was returned successfully (200 error).
Thanks if anyone can help!