Diego Gabriel is correct.
Go to Help > Install New Software and enter http://download.eclipse.org/graphiti/updates/0.11.4 as the site. Install Graphite, reboot eclipse and try to open the diagram once again.
Diego Gabriel is correct.
Go to Help > Install New Software and enter http://download.eclipse.org/graphiti/updates/0.11.4 as the site. Install Graphite, reboot eclipse and try to open the diagram once again.