Here you will find a patch which closed problems with the OrgData.
For example it closed the following problems:
- Deleting a role after you deleted users
- dissapearing roles and users
https://code.google.com/p/yawl/issues/detail?id=488&can=1&colspec=ID%20Type%20Category%20Status%20Priority%20Milestone%20Owner%20Summary&start=400