Unit of measure & not allowed for oil or natural gas quantities

What causes this issue?

You have entered a unit of measure that does not belong to one of these
dimensions: volume, mass, energy or dimensionless. For these
dimensions, standard code has been developed by SAP for the conversion
process within the Quantity Conversion Interface (QCI). If you need to
perform a conversion between quantities that have units of measure with
different dimensions, you have to write a BADI implementation for this
conversion.

How to fix this error?

Choose a unit of measure that is linked to one of the dimensions listed
above or write an implementation for the conversion using transaction
SE19 and BADI OIB_QCI_DIM1_TO_DIM2, method DIMENSION_TO_DIMENSION . For
this method, an example implementation is delivered with IS OIL Service
Pack 2, 4.6C and subsequent releases.

Error message extract from SAP system. Copyright SAP SE.