One reason that orders may end up in query is if the customer account could not be found in Xero. The error will present itself within the order like so:
You'll also see these alerts appear in the Issues Log, both in Order Issues and Synchronisation Issues.
There are two possible reasons for this. The first is that the contact record Tradebox is looking to post to has been removed from Xero and Tradebox can no longer find it. The best way to resolve this depends on how you have chosen to handle contact records in Xero.
If Tradebox is posting all your invoices to a single generic contact in Xero, then you can either recreate the contact record on Xero, or, go to the Xero tab of the channel in question and select a new contact record.
If Tradebox is creating new contact records for each buyer, then go to the Contacts section in Tradebox, click Actions > Accounts Customer Mapping. Find the relevant customer in the list of customer mappings, and allocate it to an account that does exist in Xero.
The second reason you may encounter this error can be if Tradebox has hit the Xero API limit for the day. When this happens, Xero will no longer accept further requests from Tradebox for a period of 24 hours. Because the contact record is the first thing Tradebox looks for when attempting to create an invoice, if all of your orders are showing this same query, it's likely because Xero will not allow further postings at this time. If that occurs, deactivate your channel in Tradebox and re-try again the next day.