(ORD 10.09 C#] Can't add "Cif" references to my Visual Studio project

I'm trying to create a new ORD C# project, whenever I try to add a reference to one of the "Cif" references Visual Studio shows the following error:

A reference to "C:\Program Files\Bentley\OpenRoads Designer\CONNECT Edition\OpenRoadsDesigner\Cif\Bentley.Cif.Formatting.4.0.dll" could not be added. Please make sure that the file is accessible, and that it is a valid assembly or COM component.

Didn't have this problem in ORD 10.08. I've tried targeting .NET 4.6.2, 4.7, & 4.7.2.