Removing the “Revocation information” dialog box when opening emails or visiting websites in Windows 8.1

For whatever reason, a couple days ago my computer started REPEATEDLY giving me these annoying popups whenever I would try to open an email that had an image in it (using Windows Live Mail):

Revocation information for the security certificate for this site is not available. Do you want to proceed?
[Yes] [No] [View certificate]

GAH. If an email had 5 images in it, I'd have to click Yes or No 5 times.

ANNOYING! WHY?!

So I fired up Windows Update … hooray! Can't update. Windows Update error 8024402C.

After a bit of searching, I found…

The magical Windows Update Troubleshooter!

I ran it, and yaay! Windows Update started working, AND the annoying “Revocation information” dialog boxes totally disappeared. I didn't even have to reboot.

Good times had by all.