I have a library written in C# -- Foo.dll. I am able to load rdnzl in clisp, and run simple examples that involve importing registered libs: "Hello World!", etc. No matter where I put Foo.dll, (load-assembly "Foo") results in: WARNING: Returning NULL object from .NET call NIL When I specify a full path: (load-assembly "c:\\Documents and Settings\\user\\Desktop\\Foo.dll") I get: *** - .NET error (System.IO.FileLoadException): The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047) I'm not sure what to do at this point. I am using rdnzl-0.11.0 with the included dll and Foo is compiled in Visual Studio 2005. I also get the same result using a patched rdnzl-0.5.0 compiled in Visual Studio 2008. Any Ideas? Thanks, Matt