

Part now has mass updated, but assembly does not.Because both of the files are dirtied, save dialog will pop up, save them both.Change the part a bit so it gets dirtied (also assembly will get dirtied).Create the new part (use random shape) and save it.Create the new empty assembly and save it.Check you have setting properly set "Update physical properties on save (Parts and Assemblies)".

It updates the mass of every sub-component (part or assembly), but not the top assembly, unless there is no save dialog for multiple files. It does not update the mass of the top assembly in case there is a save dialog for multiple documents. It seems update on physical properties on save (Parts and Assemblies) setting does not work properly.
