How To Fix VL742 - Essential specifications are missing for operation &1

SAP Error Message - Details

• Message type: E = Error

• Message class: VL -

• Message number: 742

• Message text: Essential specifications are missing for operation &1

What causes this issue?

There was an attempt to convert two quantities given in different units
of measure to one another, but conversion rule &v1& was specified. The
system does not allow this conversion rule. You can find permitted
values in the fixed values for domain AKMNG.
This is a serious system error.
Since this operation is a central tool that the concrete application
does not recognize, the application currently in use must specify the
cause more exactly.

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?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.