404 error on blogroll page!

This is new, and only happened since I installed 3.5; I’ve updated to 3.5.2.

I’m getting a 404 error on the static page where I have had my internal posts blogroll appearing, up till now, and had no problems previously.

Here’s the page:

https://michaelsemer.com/blog/blogroll/

Here’s an example blog post —

https://michaelsemer.com/blog/when-advertising-was-more-just-than-a-dirty-word/

Again, I’ve had no issues with this previously. I installed the Link Manager plug-in, but that’s had no effect.

It shouldn’t be the theme, as I’ve been using Blaskan successfully for 6+ months.

Any help would be appreciated!