In the most current 2.7 image (updated today), I opened a new morphic 
project, did nothing, and jumped back to MVC.  When I tried to delete 
the new morphic project, I got a notifier announcing that 
#copyWithout: was not understood in the following segment:

	"Remove Player classes and metaclasses owned by project"
(1)	is _ ImageSegment new arrayOfRoots: (Array with: self).
(2)	(is rootsIncludingPlayers copyWithout: self) do: [:playerCls | . . .

I inserted an:

	is rootsIncludingPlayers ifNil: [^true].

between lines (1) and (2), and I was able to close the project, but I 
have no idea if this was a useful "solution" at all.