WebAPI Delete not working - 405 Method Not Allowed

Question

I found the solution eventually! If you come across the same issue, add the following to your web.config

<system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules runAllManagedModulesForAllRequests="true">
        <remove name="WebDAVModule"/> <!-- ADD THIS -->
    </modules>
    ... rest of settings here

I hope this helps

In some cases removing it just from modules can produce next error:

500.21 Handler "WebDAV" has a bad module "WebDAVModule" in its module list

Module: IIS Web Core Notification: ExecuteRequestHandler"

solution was suggested here. Also need to remove it from handlers.

<system.webServer>
    <modules>
        <remove name="WebDAVModule" />
    </modules>
    <handlers>
        <remove name="WebDAV" />
    </handlers>
</system.webServer>

In my case none of the above solutions was working. This was because I had changed the name of the parameter in my Delete method.

I had

public void Delete(string Questionid)

instead of

public void Delete(string id)

I need to use the id name because that's the name that is declared in my WebApiConfig file. Note the id name in the third and fourth lines:

            config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );

I got this solution from here.

The Javascript for HTTP DELETE verb must be like this:

$.ajax({
    **url: "/api/SomeController/" + id,**
    type: "DELETE",
    dataType: "json",
    success: function(data, statusText) {
        alert(data);
    },
    error: function(request, textStatus, error) {
        alert(error);
        debugger;
    }
});

Do not use something like this:

...
data: {id:id}
...

as when you use the POST method.

After trying almost every solutions here this worked for me. Add this in your APIs config file

<system.webServer>
    <handlers>
      <remove name="WebDAV" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
    <modules>
        <remove name="WebDAVModule" />
    </modules>
</system.webServer>