Here's a list of tips that may help you fix this issue:

1. Force-close other apps before opening the game to free up the memory space on your device
  1. Go to "Settings" > "Applications" > "Manage Applications"
  2. Select the app and tap "Force-Stop"
  3. Return to the Home screen and re-start the game app
2. Reboot your device
3. Get the latest game version by checking PlayStore or by setting your Apps on Auto-update to not miss out.