If the total of your bill does not match the amount of the downloaded transaction, this error message will be displayed.
Go back to the transaction and review the totals and modify to match.
Now you have a complete history for the transaction from Purchase Order to the matching expense from the bank.
Keep the Shelf Empty
Best practice is to always keep the side shelf empty. If you still have items sitting in the shelf, most likely there is still more you can do with them.
Reviewing Your Action Items:
Send: Purchase orders that show Send have not been emailed to anyone yet.
Copy to Bill: Purchase orders that show Copy to a Bill have been emailed but not converted to a bill.
Print: Once a Purchase Order has been converted to a bill, Print will be displayed.