Posting not possible (line items from down payment not available)

What causes this issue?

You tried to transfer a down payment for the asset & &. In order to
correctly process the transaction, the system tried to read the line
items belonging to the downpayment posting. This attempt to read the
necessary line items, however, showed that they are no longer in the
system.

System Response

Transfer is not possible.

How to fix this error?

Please contact your system specialist.

Error message extract from SAP system. Copyright SAP SE.