Specify a base unit of measure

What causes this issue?

In the framework of batch determination or batch status change, an error
occured. Although there is a quantity in the base unit of measure
(stockkeeping unit) in the system, the base unit is not known.

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

System Response

How to fix this error?

Error message extract from SAP system. Copyright SAP SE.