The error you are encountering appears to be a problem at either the Google or Android level rather than a Spry Fox problem (you can do an internet search for "RPC:S-7:AEC-0" to see this for yourself--you should get quite a few results that don't involve Spry Fox games). Thus, this is unfortunately not something we have direct control over.
We found several possible remedies on the internet:
- Temporarily remove all but one account from your device (the Google account that you want to pay with).
- Please log in to https://wallet.google.com for the payment account and:
- Make sure your profile is not missing any required information.
- Confirm that you have a properly configured method of payment (credit card is not expired, etc.).
- (Exit all Spry Fox apps before doing this. Our games don't work nicely with clock changes because it often means someone is trying to cheat.) Open your Settings app and set your device's clock forward about 2 weeks, then fully exit the Settings app. Open your Settings app again and restore it to the correct date and time. This will force the device to re-sync with the Google Play servers. Now try your purchase again.
If you continue to get the same error, please contact Google Play Support by following the directions on this page: https://spryfox.zendesk.com/entries/21908615-Contacting-the-folks-at-Google-Play-Support . They will know more about the problem than we do and will hopefully be able to tell you how to resolve it.