I keep getting the error:
Warning: Virtual Directory /mxgraph not found! A virtual directory (/mxgraph) that points to the top-level directory of the mxGraph distribution is required in IIS for these examples to work. This virtual directory must be manually created using the IIS Manager.
I've created that virtual directory, converted to an application, added the directory as a web site to my solution, etc. and nothing is working.
Visual Studio is using the ASP .NET Development Server to host the application - could that be it?
Okay, I figured it out. You might want to update your instructions for those running later versions of Microsoft Visual Studio.
The references to the mxgraph virtual directory are relative, and thus assume the mxgraph virtual directory is running on the same web server as the .net application. Later versions of Visual Studio use the ASP.NET Development Web Server instead of IIS to host the application when it's being run in the development environment - it is essentially a second web server, although still on localhost. So the application is looking for mxgraph at http://localhost:52556/mxgraph (for example) but the virtual directory I created in IIS is mapped to port 80.
Updating the various references to ('/mxgraph/...') such that they are absolute paths ('http://localhost:80/mxgraph/...') fixes the issue.