Calculation results in a zero value for target quantity

What causes this issue?

The Quantity Conversion Interface (QCI) attempted to convert a
transaction quantity into a target quantity. The target quantity is
zero.

System Response

The system stops processing.

How to fix this error?

Check that a test density or test heating value is passed as input
parameters to the QCI.

Procedure for System Administrators

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.