Google Photos Upgrade to v. 1.2.1.99143001 - "Unfortunately, Photos has stopped."

A

AC Question

Moto G, Android v. 5.0.2. Was running earlier version of Photos. Took new pictures but when I tried to open Photos to see them, I was required to upgrade the app. Did so. Now I get the above message when I try to open the new version. I've uninstalled and reinstalled, shut down and restarted, with same result. I had been avoiding upgrading to Android 5.0, and thought this might be the issue. Upgraded to Android 5.0.2, but still no joy. Suggestions would be greatly appreciated. Thanks!!!