Hi Jamie,
Good news and bad news. The (relatively) good news is that the timeline items are all still there. And, they can be recovered. However, it requires an undate to Fusion. The bad news is that this fix did not make the about-to-be-released version. So, it will make the following release, which is currently planned for February. When this update happens, all your timeline items will come back.
In the meantime, I hope you can still continue to work... The design is otherwise OK, and you can do some limited editing using the parameters dialog.
The background on this bug (thanks for finding it, by the way) was that it was a problem in an early implementation of timeline groups. So, because this design was first started in that timeframe, and you were an early user of timeline groups, this problem showed up in your design.
Sorry that you ran into this...
Jeff
Jeff Strater
Engineering Director