Problem

When printing a label for Amazon Easy Ship, the following error message is returned:

Value cannot be null. Parameter name: shipmentId

Solution

The ShipmentId is a unique identifier Amazon assigns to an order when it is scheduled for Easy Ship pickup or delivery. It is required to print a label and is normally downloaded during the same sync that creates the order. In rare cases, it may come through on a follow-up sync.

The error message indicates that the ShipmentId was not downloaded, and there are a few possible reasons for this:

• Amazon Easy Ship is not enabled
  
  If none of your orders are receiving a ShipmentId, Easy Ship may not be enabled on your account.
  
  Go to Settings > Channel Integrations > Config > make sure Easy Ship Enabled is ticked:
  
  
  If it is already ticked but no orders are getting the property, contact Linnworks Technical Support.
  
  Keep in mind: If you have just enabled this setting, wait for at least one full sync to complete before reaching out to Support. Also, keep in mind that Linnworks can only download the ShipmentId for orders that have not already been printed directly through Amazon; if the label was printed on the Amazon end, the ShipmentId cannot be retrieved.
  
  
• ShipmentId has not synced yet
  
  If only one or a few orders are affected, the ShipmentId may simply not have been picked up yet, it usually arrives with the order, but can come in a later sync.
  
  To check if the ShipmentId is present, you need to go to Open Orders > click the Order ID > Properties > Extended Properties. If present, try to print once more.
  
  If it is still missing, wait 15-20 minutes and check again, then retry printing. If it still has not appeared after an hour, contact Linnworks Technical Support.