The costing lot size must not be smaller than the price unit

What causes this issue?

You have specified a <DS:DE.CK_LOSGR>costing lot size</> that is
smaller than the <DS:DE.PEINH>price unit</>. Since costing is always
based on the costing lot size, this constellation is not allowed since
it could result in rounding problems when determining new prices.

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 price unit (on either the <LS>Costing</> screen or
<LS>Accounting</> screen as appropriate) and/or costing lot size.

Error message extract from SAP system. Copyright SAP SE.