Assembly-CSharp-firstpass.dll missing from Origami

That's the problem. I got through the tutorial, and it gets stuck with hundreds of errors that boil down to Metadata file "\directory\Origami\UWP\Assembly-CSharp-firstpass.dll" could not be found

when I get to Visual Studio.

I downloaded from the links on the Hololens 101 tutorial page, on Friday last week.

Is there a quick anything I should look for? SerializationWeaver gives an error code 1 when I try to rebuild the firstpass dll on its down.