Hi Michael,

I too have had a similar problem with exporting STL from MoI over the last two Betas, but I'd just thought it was me?
Has there been some kind of "tuning" of the STL export that has now changed the way that it used to work??

Previously, I'd create a ring design & then add supports for milling, but I didn't need to join them together.
Now what I've noticed is if the model is made up of several parts, it wont export a complete STL, where previously it did.
I'm selecting ALL the parts for export, but not ALL the parts will then be in the finished STL file.

For a "work around", I've now been Boolean Union all the parts together prior to exporting as an STL from MoI.

Interestingly, if I open the same MoI design with all separate parts in Rhino, I can export a complete STL from Rhino.

regards Colin