Description
The Subnetwork name attribute fields are system-managed fields created by the Add Tier tool. The Subnetwork Field Name parameter value when adding a tier to a domain network with a hierarchical tier definition already exists but does not contain the necessary field properties.
This error can also occur during utility network creation or upgrade. Starting with utility network version 5, the SUPPORTINGSUBNETWORKNAME attribute field is added to all domain network classes. If this field already exists but its properties differ from the expected configuration, this error will be returned when creating a version 5 (or later) utility network or upgrading from version 4 (or earlier).
Solution
When adding a tier to a domain network, ensure that the specified field name does not already exist, or specify a different field for the Subnetwork Field Name parameter value.
If this error is returned during the creation or upgrade of a utility network, delete the user-defined SUPPORTINGSUBNETWORKNAME attribute field from all domain network classes and rerun the operation. This allows the system to re-create the SUPPORTINGSUBNETWORKNAME field with the expected properties and complete successfully.