Specify a reference InfoObject

What causes this issue?

The reference InfoObject specifies from which quantity DataStore object
the conversion factors for calculation are taken.
As an alternative, you can set the indicator under the rubric
'Conversion factor' for 'Override conversion of units of measure accor
ding to T006'. In this case, you do not need to specify a reference
InfoObject.
Only trivial, InfoObject non-specific conversions are allowed. With this
conversion, the function module 'UNIT_CONVERSION_SIMPLE' is used as the
basis.
Example for 1:
The reference InfoObject is '0material'. For the '0material', a quantity
DataStore object 'uommater' was generated that contains material
specific conversion factors. The factors are taken from this quantity
DataStore object.
Example for 2:
kg -> g
m -> km

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.