UML Diagram stopped working in latest release

Has anyone else experienced this issue - I'm not sure if it's only stopped working as of the latest release. Right clicking and selecting 'Diagrams > Show Diagram > Generate Sqlalchemy UML` brings up a 'building' popup and then nothing happens. No window or tab opens to display the diagram. The same thing happens with generating any UML diagram and I'm not sure why. 

The documentation mentions selecting the diagrams through the View option in the main menu but that does not display an option for Diagrams and I'm fairly certain that the documentation is outdated.