How To Fix VL354 - Quantity change not permitted; &2 &3 are packed in shipment &1

SAP Error Message - Details

• Message type: E = Error

• Message class: VL -

• Message number: 354

• Message text: Quantity change not permitted; &2 &3 are packed in shipment &1

What causes this issue?

&V2& &V3& are already packed in shipment &V1&. The delivery quantity
cannot be reduced for the quantity that is packed.

How to fix this error?

The delivery item must be unpacked using shipment processing before you
can make the desired quantity change.

Error message extract from SAP system. Copyright SAP SE.