Enter an object number set

What causes this issue?

You want to archive CO line items for profitability analysis or you
have not entered an object type. To select the objects for which the
line items are to be archived you entered group &V1&. However, this
group is neither a set for profitability segment numbers (PAOBJNR) nor
a general object number set (OBJNR).

How to fix this error?

Check the following alternatives:
Have you entered the correct object type?
If you want to archive CO line items for profitability analysis, you
must enter "PRA" as the object type. If you want to archive line items
for different object types (e.g. profitability analysis and cost
centers) in one session, you should not enter an object type.
Have you made a typing mistake?
A group with a similar name might exist that has a different reference
(e.g. cost center group). Check that &V1& is really the required group.
Do you want to archive line items for the whole profitability analysis
or for the whole controlling area?
In this case you should leave the "Group" field blank. If you do not
enter a group, all the CO line items for profitability analysis that
meet the other conditions will be archived. Other conditions could be,
for example, the chosen controlling area or the residence times.
Do you want to process just certain profitability segments?
Then you must create a general set with the internal numbers of the
profitability segments (PAOBJNR).
Do you want to process certain objects of differing object types?
In this case you must create a general object number set (a set for
field CCSS-OBJNR). We do not, however, recommend this alternative.

Error message extract from SAP system. Copyright SAP SE.