It should work ye, is it updated to the newest plugin release? Haven't seen what happens with an upgrade from 6.11 -> 6.12 yet, just separate installs. But don't think that should matter. The dashboard for 6.11 should just be ignored, and the other one loaded. It might be located somewhere else on the dashboard than before. Maybe you even need to unhide it by default if they did any changes recently to the RC. Otherwise, try to reinstall the plugin. Database should remain intact.