If you are receiving this message it could be due to a number of reasons:
1. You are signed in with the incorrect Google Play account, please use the account you purchased the app with.
2. You are not connected to the internet, you should only need to do this the first time running the app after installation or the first time running the app after restarting your device or changed network settings.
3. When receiving this message we recommend that you turn your device off and switch it on again and ensure you are connected to a stable internet connection, ideally WiFi. Ensure you are logged in with the correct Google Play account; clear the Google Play Store cache and data. Then start the application again, in that order.
To clear the data and cache of the Google Play Store application:
- Access your devices Application settings
- Select the Google Play Store app from the list
- Touch Clear Cache and Clear Data