We are sorry. Google stopped their feeds API and it was a big issue that forced us to build widget from scratch.
Yes, you need to add V2 to your workspace and update the page where that widget is located.
Best way to stay tunned is following us in Facebook.
We notice about updates there:
Since Google Feeds API closed its doors some days ago, we have completely rewritten this widget. If you see “loading” message in your widget and it does not work, you need to update it to V2. https://www.facebook.com/responsivemuse/posts/1540962999248617