Google Now and Google Play Store run into problems thanks to Google's server-side testing
The test to the Google Play Store removes everything from the home page. Yes, you can still search for apps, install them, and manually update them too. But the Play Store's home page is blank, and there is no workaround for this issue. You will have to wait for a fix from Google.
The problem affecting Google Now results in an error message appearing on the screen instead of your informative cards. However, there is a workaround here. Go to Settings > More > Application Manager > Google App > Manage Storage > Clear Google Search Data. Open up Google Now again, and your cards should be there.
As soon as we hear more about this from Google, we will pass it along to you. If you're experiencing these issues, or know someone who is, keep checking in.
source: Reddit (1), (2) via AndroidPolice