It isn’t clear what the new errors are.  They have a support page for app indexing errors, but it hasn’t been updated with any new errors at this time.

There is the possibility that Google is still rolling it out.  In a Google Webmaster help forum thread yesterday, John Mueller mentioned that the crawl errors for apps are a bit stale.

The crawl errors are currently a bit stale. I’d recommend double-checking if they’re still valid with the Fetch as Google tool, and if you’ve systematically cleaned them up, you should be fine. With the App-indexing API, you can already provide information about your app’s deep links without having to have them all crawled individually.

And a couple of months ago, Mueller also mentioned that he believed they were doing some revamping on the data.

The team is currently looking into this, to see what we can do there; I believe they’re currently revamping this data. In the meantime, one neat thing you can now do is to use Fetch as Google on an APK that you upload just for this purpose, which should make it a bit easier to double-check the issues that you’re aware of.

App indexing has become a pretty crucial part of SEO for those sites offering apps.  It is great to hear Google is offering additional or revamped data to help webmasters ensure all their app indexing content is being indexed correctly, especially as many are still learning how to do app indexing.

Added: Mariya Moeva from Google responded about the change, we should be getting details about the revamp in the near future.

Indeed, we added this short update to make things clearer for app owners who see the stale data in Search Console and might get confused. John’s advice on checking the errors in Fetch as Google still holds. Stay tuned for more updates on the revamp soon (: