Why the sync error occurs
This error occurs when an invoice marked to be emailed is attempting to sync to QuickBooks Online, but the customer is missing an email address in either Bill.com or QuickBooks Online, or the email address is invalid.
How to fix the sync error
There are two options to resolve this issue:
- Add a valid email address to the customer in Bill.com and QuickBooks Online, then sync again
- Deselect To Be Emailed on the invoice in Bill.com, then sync again