I'm getting a FS0193 in my wrapped MailboxProcessor for a web server interface I'm working on at [link:github.com] My ASP.NET sample works just fine. However, when I try to use an HttpListener in FSI, I receive this error:

error FS0193: internal error: Value cannot be null.

Parameter name: con

I don't have a parameter named con, so I assume this must be something within the MailboxProcessor or my Application type which wraps it. I can load everything in FSI just fine except the Application declaration.

The Application type is defined here: [link:github.com]

The HttpListener host is taken from Tomas Petricek's Agent example: [link:github.com]

The HttpListener use is defined here: [link:github.com]

I can't find anything on this, and I haven't figured out how to debug from FSI.

Thanks in advance for any help understanding this.

Ryan