When processing invoices in Dr Dispatch, they will fail if the customer/carrier on an invoice does not have proper Bill To information filled out.
When entering new customers/carriers/etc, the easiest way to make sure the billing address is filled out is by using the 'Copy Physical Address To Bill To Address' button on the customer tab and the 'Copy Physical Address To Pay To Address' button on the carrier tab. If the billing address is different than the physical location, you will have to manually enter it.
If you receive errors due to older customers or carriers not having a billing address then simply go back into the dispatch area and edit the applicable information. When the changes are made, you will be able to process ans export the invoice(s) to QuickBooks successfully.