I have the same issue with my "Google Account" Here's what I have noticed so far. Incidentally I got a replacement Samsung Galaxy S7 Edge yesterday and I noticed this issue after I completed the initial device setup. But it did work fine initially.
Here's what I have observed so far:
- This started happening around 9 PM CST.
- I signed up for beta testing to install updated version but that did not help.
Reinstalling Google App, clearing app cache or android cache partition does not help.
This issue is not specific to a device, it's tied to the google account. I see this on my original Samsung Galaxy S7 Edge (the one I am getting replaced under warranty), My wife's Galaxy S7 Edge(when I add my account to her device) and for that matter even on my Nexus 2012 tab.
Adding a different google account resolves the issue. This is not an ideal solution though, since Google now cards are based on data from google account and using alternative google account will not show you cards which are relevant to you.
Another possible solution, but it has limitations:
Navigate to Google App settings -> Account Privacy -> Google activity controls and turn on Web & App activity. Go back to google now cards and swipe down on screen to refresh. Google now cards start working and the "New version available" message is not seen any more.
Limitations: You will not get cards related to traffic updates, location, cards based on your web and app usage. This pretty much beats the purpose of using Google now cards.
Extremely frustrated with this issue. Hopefully there is fix available soon.