Diagrams based on the Standard or Network Dataset builders may not be correctly generated, updated, and saved while an edit session is open when the related schematic feature classes and the edited feature classes are in the same physical workspace (database) except when you are working with a file or a versioned ArcSDE geodatabase.
Working with a personal or nonversioned ArcSDE geodatabase when the physical workspace is edited
When working with a personal or a nonversioned ArcSDE geodatabase, any newly generated diagram or changes after updating/saving a schematic diagram will be correctly stored in the schematic database only if the edit session is saved before closing. When the edit session is closed without being saved, the generated diagrams, the changes on the updated diagrams, or the edits on the saved diagrams that happened during the session are lost.
Working with a file or versioned ArcSDE geodatabase when the physical workspace is edited
Generating, updating, or saving edits on schematic diagrams while the Schematics physical workspace is being edited works with file or versioned ArcSDE geodatabases without any particular constraint.