The blog URL link on Jay Hanlon's profile page is broken.
It's currently pointing to: https://blog.stackexchange.com/author/jhanlon/
The correct blog URL address is: https://blog.stackexchange.com/authors/jhanlon/
Looking at the two URLs above, you can see the reason for this broken link. The directory name was changed.
Team members (or blog authors in this case) at the newly re-design Stack Exchange blog are now moved to the authors (as opposed to author) directory. This problem would not have arisen at all if the directory name was not changed.
But, Jon Chan and his team might have some valid reason for this directory name change.
Instead of posting a new bug report, I originally thought of reporting this directly to Jay via email, (as some of the SE team members do include official email address in their Profile) but, I was out of luck in this case.