I am trying to implement an Options method in a controller of my web service that will return a message containing the valid HTTP methods for the URI endpoint associated wit
If you use Glimpse, you might have to disable it's route inspector:
Glimpse creates RouteProxies that break enumeration in HostedHttpRouteCollection: https://github.com/mono/aspnetwebstack/blob/master/src/System.Web.Http.WebHost/Routing/HostedHttpRouteCollection.cs
I know the link is for mono but the same is true for standard .Net.