I have tried printing a Amazon Shipping label and am seeing following error returned where the "x" is replaced with a number:

INVALID_REQUEST: 1 validation error detected: Value null at 'containers.x.member.items.x.member.qualifiers.x.member.value' failed to satisfy constraint: Member must not be null


This error usually is being returned because an item on the order does not have either dimensions or weight applied to it. Item weights and dimensions can be added and updated manually in > Inventory > My Inventory > click on a SKU > Product Details > Postage Definition.

Typically the order weight and dimensions would need to include the weight and dimensions for the packaging itself in order to be correctly passed on to the vendor when generating the shipping label. Those can be added in > Shipping > Packaging Groups.

If you view the order in Open Orders screen, then you can check which Packaging Group and Type is assigned.

NB! If you have ensured that the item(s), packaging and the order itself have both weights and dimensions assigned, but the error is still returned, please contact Linnworks support for further assistance in resolving the error.

Related articles:

Shipping - Adding shipping details to items