Diagrams can be edited using the ArcGIS Schematics SDK. As such, it is important to follow the correct pattern for editing diagrams, specifically to not load the diagram in memory prior to attempting to edit or hold a reference to the in-memory diagram when calling StopEditSchematicDiagram. Loading the diagram in memory is handled internally by the Schematic Layer during StartEditSchematicDiagram. Additionally, loading the diagram in memory within the custom code as part of the diagram editing process adds a reference to the in-memory diagram. Holding a reference to the in-memory diagram when calling StopEditSchematicDiagram may result in a crash or prevent the in-memory feature classes from being released internally by the framework.
When editing schematic diagrams using the ArcGIS Schematics SDK, the following workflow is recommended. Please note the difference in the two referenced function calls.