Opening Diagrams
If the UModel project contains diagrams, these are displayed in the Diagram Tree window.

Diagram Tree window
Note: By default, diagrams are grouped by type in the Diagram Tree window. To display only diagrams (without parent groups), right-click inside the window and clear the Group by diagram type context menu option.
Diagrams are also displayed in the Model Tree window under the packages where they belong, for example:

To open an existing diagram:
•Double-click the diagram icon in the Model Tree window (or in the Diagram Tree window, or in the Favorites window).
•Right-click the diagram, and select Open diagram from the context menu.