since updating my S7 edge to android 7.0 I can no longer open google play store. I've cleared cache and data, time and date are good, uninstalled updates and installed newest apk.
Just wondering whether you've signed back into your Google account following the update.
I only ask because I received a notification from Google to sign back in, which I duly did, then looked to see whether a software update was available, which there was. So the two could be connected.
Worth a try.