well i just encountered the same, was messing around in wip a few minutes all objects disappeared after which rhino went to the beach and never returned. i just installed the newest wip, before i never saw this happening.
i made a spin dump should someone need it.
There is a new WIP out (again) that should fix these problems. So sorry about this!
Very silent announcement for such a problem.
RH-90586 is fixed in Rhino WIP