QBWC1012: Authentication failed due to the following error message. Server was unable to process request. You have synced more sales than your license key allows. Go to connexforquickbooks.com/log for more information"
This happens when you're using a trial version of a third party app and you've exceeded your trial.
What you can do?
1. Update Web Connector to the latest version.
2. Update your License Key.
Note: If you still get this error, reach out to Intuit Support.