I delete the IM Gateway plugin while i have one client using the gateway and after that I cannot see the plugin anymore even after the server upgrade. I have experienced it before (2.1-2.3 ?) and gato have opened Jira issue and solve it. Now it is happening again with 3.0 and IM gateway plugin. I need to get back my database from back up to make the plugin reappear( I am using MySQL 4.)
thx