Partner unit not filled

What causes this issue?

The current data record contains no characteristic value for the
characteristic 'partner unit'. However, specification of a partner unit
is required for consolidation postings at posting level &V1&.

System Response

The system cannot process the current data record.

How to fix this error?

Make sure that postings are to be made at posting level &V1&. For data
records of this type, ensure that there is a valid characteristic value
for the characteristic 'partner unit'.

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.