As soon as I hit copy it tells me that one of the files in the subfolder (presumably the first file it encounters) already exists, even though the target folder was empty to start with.
Okay, it seems the easiest solution is to use the VisualBasic implementation of CopyDirectory. It might seem like a simple task, but its surprisingly difficult to copy a folder with subfolders into another folder (and obviously a lot that can go wrong if you are not careful).
Even though it is a Visual Basic method, it’s actually part of .NET.
So you can add Microsoft.VisualBasic.Core.dll as a file reference (its in the vvvv folder in “refs”).