This error means that either the item has been sent across to Xero but then deleted, or has been published as an expense.
Before taking the following steps, please make sure that the item is not in your ‘Expenses claims’ section within Xero.
1.Select the item in your Inbox (tick the check box). You can try the ‘Advanced search’ engine, next to the ‘Supplier search’ box.
2.Click the 'Tools' button on the menu at the top and choose 'Clear publishing data' option before publishing.
3.Re-publish the item from your 'Inbox' by clicking the 'Publish' button.