Important steps if your game isn't working after 1.18 (Aug 2017) update
After being told to reinstall the game 70x by 6 different people, I finally got someone from EA to realize there's a bug in the game. They asked us to do the following:
1) Go here: https://help.ea.com/en/plants-vs-zombies/plants-vs-zombies-heroes/. Scroll to the bottom. Click "Contact Us". Select your device. Under topic, select "Report a Bug", and then under issue, select "Report a Bug". Then, select contact option, and send them an email. Apparently this is the only way to reach the developers, even though the website tells you not to do this if the issue prevents you from playing the game.
2) They also want to get a list of everyone this is happening to since it's across multiple platforms. Please list your PVZ Heroes username below if it's happening to you!! I'll report all the usernames I get.