Quantity Conversion Interface: error in structure &

What causes this issue?

An error occurred while the system was matching the fields of the
structure maintained in Table OIB04 for the HPM quantity conversion
import/export parameters.

How to fix this error?

Check the import/export structures maintained in Table OIB04 for the
conversion routine. Important conditions to check are: spelling, length,
type, order sequence, and so on. (Transaction O588)

Error message extract from SAP system. Copyright SAP SE.