Here are a few troubleshooting options:
1) Apps need to be renewed every year in the Amazon Appstore. Please click on one of the links below and make sure ScanLister is still active.
2) Please double check that your Seller ID and Auth Token are correct.
3) Make sure you are using the latest version of ScanLister.
4) Make sure the decimal format on your computer is a decimal and not a comma.