We are using Raygun on an ASP.NET web project that consists of both MVC and WebApi. We are also using OWIN for integrating the webapi pipeline as our web services are secured by OAUTH. This means we use the app.UseWebApi() in the Owin startup class.
We have configured Raygun on both the MVC and the WebApi pipeline as described in the Raygun documentation.
The problem occurs when trying to access an MVC controller action that has one or more parameters. In this case the request fails with a "This method or property is not supported after HttpRequest.GetBufferlessInputStream has been invoked." exception.
After looking at the Raygun sourcecode I have found that when WebApi is used together with Owin the RaygunWebApiDelegatingHandler is called for MVC controllers as well - this is not the case when Raygun WebApi is configured like normal in the global.asax.
I have made a POC project showing the problem - which can be downloaded here:
In Global.asax, Startup.cs and WebApiConfig there are some comments describing the problem and how to reproduce it.