ASP.NET Web API - PUT & DELETE Verbs Not Allowed - IIS 8

Question

I recently upgraded from Visual Studio 2010 to the Visual Studio 2012 RC. The installer also installs IIS 8 Express which Visual Studio now uses as the default web server.

IIS 8 is blocking my WEB API requests that use PUT AND DELETE verbs. IIS returns a 405 error, The requested resource does not support http method 'PUT'.

I know people have issues with this in the past and there are several messages about it on Stack Overflow. With IIS 7 Express the solution was to uninstall WebDav. Unfortunately I don't see any way to do that with IIS 8.

I've tried editing out the WebDav sections from applicationhost.config but that hasn't helped. For example I removed <add name="WebDAVModule" image="%IIS_BIN%webdav.dll" /> from the config file.

I've spent far too long on this. There must be a simple way to enable PUT and DELETE?

Answer 1

Okay. I finally got to the bottom of this. You need to jump through some hoops to get the PUT and DELETE verbs working correctly with IIS8. In fact if you install the release candidate of VS 2012 and create a new WEB API project you'll find that the sample PUT and DELETE methods return 404 errors out of the box.

To use the PUT and DELETE verbs with the Web API you need to edit %userprofile%documentsiisexpressconfigapplicationhost.config and add the verbs to the ExtensionlessUrl handler as follows:

Change this line:

<add name="ExtensionlessUrl-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />

to:

<add name="ExtensionlessUrl-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />

In addition to the above you should ensure WebDAV is not interfering with your requests. This can be done by commenting out the following lines from applicationhost.config.

<add name="WebDAVModule" image="%IIS_BIN%webdav.dll" />
<add name="WebDAVModule" /> 
<add name="WebDAV" path="*" verb="PROPFIND,PROPPATCH,MKCOL,PUT,COPY,DELETE,MOVE,LOCK,UNLOCK" modules="WebDAVModule" resourceType="Unspecified" requireAccess="None" />

Also be aware that the default Web API convention is that your method name should be the same as the invoked HTTP verb. For example if you're sending an HTTP delete request your method, by default, should be named Delete.