Since last night (10/18), getting "error occurred (-50)" trying to log into iTunes Store. Is there an issue with the iTunes Store?

That's the error I've been getting since last night.

I thought it was an issue with my network card, but it isn't since everything else connects-- web browsers, Skype, CrashPlan Backup client, Spotify, etc. Re-installing the drivers didn't work either.

I thought it was an issue with Avast 2014 (free edition), but it isn't since iTunes.exe is already on the Exclusions list, and disabling Avast didn't fix it.

I thought it was because of the Windows 8.1 update, but it isn't since I was listening to iTunes Radio shortly after the update and was connecting fine to the iTunes Store immediately after.

I thought it was iTunes itself so I reinstalled it but the error still came up.

So, it isn't my end but something else.

What could be causing the the error?

PC:
Windows 8.1 Pro with Media Center (64-bit)

16 GB DDR3 RAM

Intel Core i5 2400

ASrock Z68 Gen 3 Extreme 3 board

Intel GigabitCT NIC