My name is Tim Zook, I’m the lead developer for MyBookTable. I ran some tests and nothing appears to have changed with the Amazon integration for us, the Amazon Reviews and Amazon Book importer are working fine, so it must be something with your account configuration. It’s hard to give much detailed advice without being able to see your account setup, but I would try migrating your credentials if you have the option, you can always re-create your credentials set if it doesn’t work. You can find more detailed information on managing your Amazon Access Keys in Amazon’s documentation.