You probably have the track status set to show events connected to specific track(s). In this case once you click out of a new event it will disappear. Once you change the track status to show all events your new event will be displayed. If you are trying to create a new event then connect it to one of the tracks, you can do this by using the connection tool to click on the track to which you wish to connect the event.
Tag: StoryView, Outine 4D