Unable to delete Quantity Conversion in Product Master Data

[SAPSupport]

Error occurs while trying to update the quantity conversion in the product master data.
Error: 'Changing the conversion not possible; it is used by one or more open customer invoices, items to be invoiced, procurement price lists, purchase orders, purchase requests, sales orders, source documents, source documents for supplier invoices, supplier invoices and supplier credit memos'

Is it possible to change/delete the quantity conversion?

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[SAPSupport · Accepted solution]

The relevant material or service is already used in one or more documents. The reason for this error is that the business documents which are using this material would end up in inconsistency if the change is allowed. The veto check executed is not at quantity conversion level, but rather at material/service level. If that material/service is being used in a document, even if the quantity conversion used is one other than the one you intend to delete or change, the system will still block the action.

Since the quantity conversions are already used in business documents, system will not allow the changes at master data level. Changes to the quantity conversion directly in the backend are also not supported by SAP. As a workaround, SAP advises to create a new material with the same details as the existing one, maintaining the correct quantity conversions, then blocking the previous material/service for further use.