1. Vendor or Account not Found. 

The Vendor or the GL being used does not match QBs. Confirm Vendor Linking (More - Vendor Linking) and Item Mapping (Full list under Account Split Summary). Both need to be the exact same as listed in QBs. 

2. Terms don't match.

Terms listed in Plate IQ have to be part of the Terms List in your QBs. 

For more information on this please see how to add and edit net terms.

3. Vendor Name Wrong, or not created in QBs.

Vendor ID in PIQ does NOT match the one in QBs for the vendor. They also have to ensure it's already created and active in QBs. To edit, they can click on More -> Edit Vendor Mapping or from the Vendor Center -> Select the Vendor -> Accounting -> Pencil to edit.

4. Locked by another Company File.
A QuickBooks company data file is already open and it is different from the one requested or there are multiple company files open.
To fix, they have to ensure they only have one Company File opened at the time of sync. Signing back in to QBs to just that one file works best.
If the issue persists, have them select on "Click for more information" and send the logs. If the error is the same you can go to Accounting - Restaurant Account, for such cases, you can delete the accounting_file_location and ask them to retry.

5. Invoice Date outside of the Closing Date. You would need to ensure the Invoice Date and Posting Date (if applicable) are within your Accounting Software's current period.