Subitem &2/&3 of document &1 not transferred

What causes this issue?

The subitem &V2&/&V3& from document &V1& is to be transferred although
other open subitems still exist. This is not permitted.

System Response

The affected subitems are not transferred.

How to fix this error?

Select all subitems for transfer.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.