Hi PaQ, so one odd thing is that if you have any annotation text objects in your model (Dim > Text), it will write out a Rhino v5 .3dm file to make some text properties go into Rhino ok. So one side effect is that should also make your mega version save work ok as well in the current MoI beta.

So if you want to give that a try, go to Dim > Text and place an annotation text object anywhere after you have done the 20 copies, then you should be able to save it ok. I guess you'll have a 9GB or so file size, does that actually work?

- Michael