Answer
An edge-edge connectivity rule has been established and a default junction assigned to the rule. When a new edge is created, which is connected to another edge specified in the connectivity rule, the default junction is not present at the intersection of the edges.
There are several different circumstances in which this problem may arise:
1. A new edge feature is created and snapped to the endpoint of an edge or to a junction connected at mid-span to a complex edge. The default junction of an edge-edge connectivity rule is only created when an edge is snapped along or at mid span to another edge. If you snap a new edge to the end of an edge or to a junction along mid span of the edge, the default junction will not be created. The existing junction will not be subsumed by the default junction specified by the connectivity rule that exists between the two edges. While this may violate the connectivity rules you've set in place, the rules are not actually enforced until Validate Selection is performed.
See the ‘Subsume Junction with Default' sample code in ArcObject Developer Help. This sample adds the default junction for an edge-edge connectivity rule when an edge is snapped to the end of an edge.
2. If you are creating a new edge along or at mid span of an existing edge, where no junction currently exists, and the default junction is not inserted:
- Verify that the junction is still defined as the default junction in the Network Properties dialog in ArcCatalog.
- Verify that you’re snapping environment is defined properly. If you're trying to snap an edge along an existing edge, make sure the Edge check box for the edge feature class you are snapping to, has been checked.
3. If you have verified that your snapping environment is defined properly, the 'Create new feature' tool may not be snapping to a feature when you're creating the new edge. Move the 'Create new feature' tool towards the feature until you see the cursor snap to the feature. If you cannot see the cursor snap to the feature, zoom in to a larger scale. If this still does not work, increase the Snapping Tolerance on the General Tab under Editing Options.