Proportion and product units are not allowed as lower-level units

What causes this issue?

The unit of measure &V1& is a <DS:DE.LRMEI_WS>proportion unit</> or
<DS:DE.LRMEI_WS>product unit</>. These units of measure are not allowed
as lower-level units.

System Response

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

How to fix this error?

Change the lower-level unit.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.