The value &1 is not allowed for the characteristic &2

What causes this issue?

The value you wanted to assign to the characteristic &V2& is not a unit
of measure.

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?

You have the following options:
Choose another value for this characteristic.
Ask your system administrator to define the value &V1& as a unit of
measure in Customizing for <LS>Global Parameters</> in the activity
<DS:SIMG.SIMG_CFMENUOLMSOMSC>Check Units of Measurement</>.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.