I have tried printing an Endicia shipping label and am seeing an error returned:
ERROR: Label 64055: SM Parcels Ground is not allowed. Error encountered (Log ID: XXXXX)
Please first review if the order has a correct Endicia postal service assigned that allows to ship to the destination address. You can try to use Get Quotes functionality to see if any available services are returned.
There also might be an issue on Endicia's side. You can contact Linnworks support and we can provide you the API request/response files and those can be provided to Endicia for further clarification on the issue.
Shipping - Get Quotes is not producing any/expected services