It's possible to revert to an earlier state of the document

[pvh]

I created a chat gizmo and shared it between two of my computers. On reopening the document on the originating computer it was missing the reply from the second. I haven't dug in but for my own reference it was a chat named 'radchat'.

[pvh]

This appears to have happened when I had two copies of the same window open. One of them received updates and the other did not.