A client was getting errors when using PUT/POST/DELETE verbs on their web application recently.

The errors he was seeing were:

<h2>405 - HTTP verb used to access this page is not allowed.</h2>
<h3>The page you are looking for cannot be displayed because an invalid method (HTTP verb) was used to attempt access

After some troubleshooting the error was isolated to the fact that WebDav was installed on the server and was intercepting those requests for its own service use.

Rather than removing WebDav from the server, we went looking for another solution. Thankfully someone on Twitter understood the issue and gave an example of changes to make to the client’s web.config file in order to disable (remove) the WebDav module for just that specific site without requiring any manual administrative actions on the server.

The code updates to make to your web.config file to resolve this error are:

<configuration>
  <system.webServer>
    <handlers>
      <remove name="WebDAV" />
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
    <modules>
      <remove name="WebDAVModule" />
    </modules>
  </system.webServer>
</configuration>

I hope this helps. Happy hosting!