ExtensionlessUrlHandler and "Recursion too deep; the stack overflowed" : <p>I'm trying to get a fellow developer's app working on my machine. Solution is built in VS 2015 using Web API and I'm running it using 64-bit IIS Express. Every request is returning 500.0 errors. Request tracing log says this about it:</p>

<pre><code>1517.  -MODULE_SET_RESPONSE_ERROR_STATUS 
ModuleName    ManagedPipelineHandler 
Notification  EXECUTE_REQUEST_HANDLER 
HttpStatus    500 
HttpReason    Internal Server Error 
HttpSubStatus 0 
ErrorCode     Recursion too deep; the stack overflowed. (0x800703e9) 
ConfigExceptionInfo
</code></pre>

<p>The relevant config section looks like this:</p>

<pre><code>&lt;system.webServer&gt;
&lt;handlers&gt;
  &lt;remove name="OPTIONS" /&gt;
  &lt;remove name="OPTIONSVerbHandler" /&gt;
  &lt;remove name="TRACEVerbHandler" /&gt;
  &lt;remove name="ExtensionlessUrlHandler-Integrated-4.0" /&gt;
  &lt;remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" /&gt;
  &lt;remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" /&gt;
  &lt;add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*" verb="*" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" /&gt;
  &lt;add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*" verb="*" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" /&gt;
  &lt;add name="ExtensionlessUrlHandler-Integrated-4.0" path="*" verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" /&gt;
&lt;/handlers&gt;
&lt;/system.webServer&gt;
</code></pre>

<p>Other possibly relevant facts:</p>

<ul>
<li>The machine hasn't been used for web hosting before, but I've been doing a lot of VS2013 development and only installed 2015 last week to run this project.</li>
<li>The project does contain some C# 6.0 features, namely the new string interpolation goodies.</li>
</ul>

<p>How would I even begin to debug this? I'm getting zero relevant hits on Google.</p>
