Why am I getting a 404 error in Magento when posting invoices?

Overview

When you try to process your order sync queue or your cron job runs, a 404 error occurs and nothing is posted, all orders remain in the order sync queue.

Environment

Magento

Resolution

• This error indicates there are transactions which belong to a store which you have removed from your configuration
  • Remove those transactions from the Avalara Order Sync Queue and process as normal