is SwDocumentMgr 32bit only?

I downloaded an example, and visual C# express compiles it fine, but it won't run, giving me the following error:

Unhandled Exception: System.BadImageFormatException: Could not load file or asse

mbly 'Interop.SwDocumentMgr, Version=19.0.0.0, Culture=neutral, PublicKeyToken=n

ull' or one of its dependencies. An attempt was made to load a program with an i

ncorrect format.

   at DocMgr_CS.Program.Main(String[] args)

I think express will only generate 64bit programs (I have a full copy of visual studio at hand.)  Is that likely the problem, or is SwDocumentMgr expected to work in 64bit mode?

SolidworksApi macros