The app does not start by "error code:0"

If the "error code:0" is displayed, please try the following.

Sign out and Sign in to the App Store with your Apple ID

1. Tap "Settings" of your device
2. Tap "iTunes ＆App Store"
3. Tap "Apple ID" and choose "Sign out"
4. Sign in with your Apple ID that you signed in when you installed Grand Sumo app

After that, Please start Grand Sumo app and check that error doesn't occur.