Make sure you have a stable internet connection over wifi, 3G or 4G (additional data charges may apply, please use wifi where possible). You can archive your issue and download it again. To archive your issue please see the FAQ "How do I delete or archive an issue I've downloaded?".
If your issue still doesn't work correctly you can delete the App from your device and install it again. Although this may sound extreme it is often necessary. You won't lose any of your purchases but you will need to download issues again.
To delete the App from your Apple device please refer to this helpful guide
To delete the App from your Android device please refer to this helpful guide
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