@everyone The widget’s previously cached posts were cleared during the update, so it will take a little while for new posts to start appearing. We’ve had to make that change as we switched to use HTTPS for all Stats requests in Jetpack 4.5. Sorry for the trouble!
I checked all of your sites, and all of them (when the widget was still active on your site) had at least one Top Post being displayed. With time, more posts should start appearing in your widgets if your site gets visits.
Until that happens, I would suggest that you all go to Appearance > Widgets in your dashboard and make sure your Top Posts Widget settings are set as you want them to appear.
If you still experience issues tomorrow, let me know!