... do you know how you got to https
://www.webmasterworld.com/featured.htm, which contains the bad link? Did you navigate to it, and do you have any idea from where? Or was it an old bookmark? The page is an old WebmasterWorld "front page" (copyright date 2014). As keyplyr describes, yes, it could be a page that's left over from the change-over to responsive, perhaps referenced in an old discussion... but that doesn't help us much.
Chances are that Brett might know whether it should have been redirected or deleted.
The "recent posts" (top-nav) link you clicked on goes to https
://www.webmasterworld.com/active.htm, which no longer exists.
Worth re-emphasizing the thread not2easy cites.... [webmasterworld.com
...] which not only discusses 404s links to obsolete pages, but explicitly mentions a "recent posts" link, and it also mentions log-in
It is the link to Recent Posts after you login.
Both of the log-in links in that discussion now return 404s, so maybe they've been cleaned out.
You mention above...
Not a biggie, but when I'm logged in and on this page:
Possibly that's an area with some legacy issues.
I'll report this discussion and see if it leads to anything. Thanks for the description.