Inconsistent item data for &2 &1

What causes this issue?

An error has occurred when the provider contract or partner agreement
data was created or changed using the BAPI interface. The attributes
that were transferred for the contract &V1& with the structure &V2& are
not consistent for at least one item of the provider contract or partner
agreement.

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?

Check if all required entry fields are filled correctly at the BAPI
interface:
CONTRACTITEMDATA:
When an item is created and changed, the GUID has to be filled in the
field CONTRACTITEMID.
Each CONTRACTITEMID may only be transferred once.
The field CANCL is not supported. The BAPI BAPI_CTRACBILLCONTRACT_DELETE
can be used for the reversal of an item.
TECHNICALRESSOURCEDATA:
When technical resource data is created and changed, the GUID has to be
filled in the field CONTRACTITEMID.
DISCOUNTDATA:
When technical resource data is created and changed, the GUID has to be
filled in the field CONTRACTITEMID.
SERVICETYPEDATA:
When service types are created and changed, the GUIDs have to be filled
in the fields CONTRACTITEMID and the field SERVICE_TYPE.
PRODUCTCONFIGDATA:
When having to create and change product configuration data, the fields
CONTRACTITEMID and the fields CONFIGID, ROOTID, INSTANCEID and PARENTID
have to be filled in all tables as far as it is available on the
interface.
Each CONTRACTITEMID may only be transferred once.
BILLINGPLANHEADERDATA:
When header data is created and changed to the billing plan, the GUID
has to be filled in the field CONTRACTITEMID.
Each CONTRACTITEMID may only be transferred once.
BILLINGPLANITEMERDATA:
When item data for the billing plan is created and changed, the GUIDs
have to be filled in the fields CONTRACTITEMID and the field BIPITEMREF.
Each combination from CONTRACTITEMID and BIPITEMREF can only be
transferred once.
BILLINGPLANREFDATA:
When object relationships are created and changed to the billing plan,
the GUID has to be filled in the field CONTRACTITEMID.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.