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Network Topology Error Solutions

Sep 16, 2025

Overview

This lecture reviews common network topology errors in the ArcGIS Utility Network and provides step-by-step solutions for identifying and resolving each error.

Common Utility Network Topology Errors

Invalid Connectivity: No Junction Edge Rule (Error code 8)

  • Occurs when a point feature connects to a line but no valid rule exists allowing their connection.
  • Fix by adding a missing junction-edge rule or correcting the feature’s asset group/type.

Invalid Connectivity: More Than One Junction Edge Rule Applicable (Error code 9)

  • Happens when multiple rules enable a point-to-line connection, causing ambiguity.
  • Resolve by removing invalid rules or specifying the correct terminal connection with the Terminal Connections tool.

Invalid Connectivity: Edges Are Different Subtypes and Cannot Connect (Error code 10)

  • Triggered when two lines of the same asset group but different types connect without a junction.
  • Fix by making asset types match, merging the lines, or inserting a valid connecting point feature.

Line Feature Has Invalid Terminal (Error code 36)

  • Indicates line terminal fields (ToTerminal/FromTerminal) reference invalid or missing devices.
  • Correct by updating terminal fields to 'None' if unconnected, or setting them correctly if a device is attached.

Unsupported Structural Attachment Relationship (Error code 35)

  • Arises when a structural association exists without a supporting rule between the involved features.
  • Fix by deleting the association, updating the attachment to a valid feature, or removing the incorrect attachment.

Subtype or Discriminator Out of Range/Invalid Combination (Error code 23)

  • Caused by asset group/type values outside permitted domains, often due to migration.
  • Address by selecting valid coded values or mass updating fields.

Stacked Point Features (Error code 25)

  • Occurs when two point features occupy the same x, y, z location but are not valid coincident features.
  • Fix by deleting duplicates, moving a feature, or updating its Z value.

Point Feature Has Invalid Terminal Configuration (Error code 39)

  • Happens when the terminal configuration field is populated with an invalid path.
  • Correct by setting a valid path using the Terminal Paths tool.

Key Terms & Definitions

  • Junction-edge rule — Defines valid connectivity between point (junction) and line (edge) features in a utility network.
  • Terminal — Logical connection points on a device, used for advanced tracing and network management.
  • Structural association — A modeled relationship between structural and non-structural features, such as a pole and transformer.
  • Asset group/type — Classification identifiers for features, controlling rules and connectivity.

Action Items / Next Steps

  • Practice identifying and resolving sample topology errors using ArcGIS Pro tools.
  • Review the suggested readings and tutorials on managing topology errors with the Utility Network.
  • Validate your utility network topology after edits to check for and fix errors.