With price control V, enter a moving average price

What causes this issue?

Price control indicator "V" is set, but no moving average
price/periodic unit price entered.

System Response

Though it is necessary to enter a moving average price/periodic unit
price for the system to valuate the stock of the material correctly
when goods movements are made, it is not mandatory to do so at the
moment. The system updates the price here automatically at the time of
the first goods movement at the latest.

How to fix this error?

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.