Object number set &1 contains the object type &2

What causes this issue?

To limit the line items to be archived you entered the general object
number set &V1&. This object number set contains at least one object
number with <DS:GLOS.3552CF13CEA7323BE10000009B38F984>object type</>
&V2&.

System Response

During the selection the system ignores all the lines in the set where
the object type meets one of the following conditions:
For the objects of this object type there are no line items in Cost
Accounting
The object type is not supported by the Archiving CO Line Items
function
Objects of this object type are selected with other objects. This
applies for the object types NWA (network activity), ORI (order item)
and ATY (activity type). Objects of these object types automatically
archived with the superior objects of object types NWK (network), ORD
(order) or CTR (cost center).
CO line items for this object type are, according to Customizing, not
to be archived

How to fix this error?

If possible, you should not use a general object number set. For
further information on the input possibilities, see the F1 help for the
<DS:DE.COOM_ARC_SETNAME>"Group or set"</> field. Here you will also
find an overview of the object types supported and which object types
can be selected directly.
Check that the Customizing for archiving CO line items has been
maintained correctly. All object types for which you want to archive
the line items must have at least one entry where the flag "do not
archive" is NOT active.
Enter object number sets that contain meaningful object types.

Procedure for System Administrators

If line items exist in Cost Accounting for object type &V2& and this
object type is not supported by CO_ITEM archiving, contact your SAP
hotline. Note, that some object types are only supported implicitly,
such as NWA (network activity), ATY (activity type) and ORI (order
item).

Error message extract from SAP system. Copyright SAP SE.