Hi. I have problems with Activiti Modeler: Run Activiti Explorer, and if i try to edit the chart runs Activiti Modeler, but the editor does not start completely. Maybe I'm doing something wrong? (Alfresco Communiti 4.2c, Activiti 5.11)
Use firebug (or your favorite browser-debug-tool) to see what http-requests are done. Most likely, there will be failures in the net-console. You can get started from there.