Error in quantity translation in CO-PA valuation using conditions

What causes this issue?

In Profitability Analysis (CO-PA), the system tried to use conditions
to translate the unit <ZH>&V2&</> for the material <ZH>&V1&</> into the
base unit of measure <ZH>&V3&</> for that material.
This was not possible.

System Response

The document cannot be processed any further.

How to fix this error?

Check the quantity in the affected CO-PA quantity field (<ZH>&V4&</>).
If necessary, change the material master to allow the unit <ZH>&V2&</>
as an alternative unit for the material <ZH>&V1&</>.

Error message extract from SAP system. Copyright SAP SE.