I'm assuming that you do have connection on your device while attempting this, and you've checked while trying. Moving on it sounds like the type of error that you might get if your credentials were messed up. If the PS app will even open try signing out and signing back in to your Google account. If it won't even open to allow you to sign out go to Settings>Apps>All scroll down to PS and clear data, not the cache but that probably wouldn't hurt either, that should sign you and force you to enter your login info upon launch. If that doesn't work try uninstalling the update from the same location.