i'm new in Activiti. I just installed the Eclipse 64bit and the activiti designer plugin 5.9.1 how said in the user guides.
I have create a new diagram by copy&paste from here http://activiti.org/userguide/images/FinancialReportProcess.bpmn20.xml and open it with the activiti perspective. All fine, I see the flow. But when I try to do something and save, I close the prospective and I open the file xml to see the modification, I see only an empty file. I try to reopen with the activiti perspective but is also empty. I try also with easy modification, only move a little bit over an element, but still doesn't work.
I try also to erase my workspace, eclipse and install all new copy of it and of the plugin, but still doesn't work.
Thanks for reporting this. The problem is that the Designer expects the start and end event names to be filled. Therefore the generation of the XML failed and the process is empty after save. I've fixed this in trunk.