Let's say you link a article that hasn't been created yet, clicking that allows you to go to the edit page for it.
Now instead of doing that, type the article name in the URL, which should take you to the article page that shows you the system message from "MediaWiki:Newarticletext". On my wiki, it instead shows the 404 page error. I'm not quite sure whats going on but the Cloudflare logo is at the bottom.
Is that a public wiki (link welcome)?
Has this been brought up yet on https://www.mediawiki.org/wiki/Project:Support_desk ?
Also wondering if https://www.mediawiki.org/wiki/Manual:How_to_debug might help here (but not too convinced).
MediaWiki returns an HTTP 404 error code on non-existing pages. It looks like Cloudflare is trying to be "helpful" by overriding the default MediaWiki output with its own error page. Perhaps you can tell Cloudflare to ignore 404 errors on your wiki; I know nothing about that particular platform. Or alternatively put $wgSend404Code = false; in your LocalSettings.php file.
In any case, this is not a MediaWiki bug (as should have been evident from the Cloudflare logo on the page in question). Please discuss general MediaWiki issues at the Support Desk instead.
@TTO, thanks for the help and as well @Aklapper. I'll try the code you gave me to see if it works. Again, thanks!
I realized it wasn't a MediaWiki bug after I saw the Cloudflare logo, but it wasn't a bug for Cloudflare as well. Cloudflare was only taking a article page (that hasn't been created yet) as a file/location that did not exist at all.
This is called "SmartErrors" (however ironically) and is an optional 'feature' which can be disabled from CloudFlare's user interface. See https://www.mediawiki.org/wiki/Manual:CloudFlare#Error_404_handling
This so-called "feature" has now been permanently removed on Cloudflare's side. That should stop this issue from arising again.