For excrement and merriment, I downloaded the latest installation file for MSE, turned off my internet connection, uninstalled MSE, then reinstalled MSE. After the automatic download of definitions failed (as expected) at the end of installation, I reconnected to the internet, and ran the MSE updates again. The one that downloaded was 1.143.466.0. I immediately manually downloaded the definitions and wound up with 1.143.548.0. If this doesn't get fixed soon, I'm considering going back to AVAST! free.