HTTP 404 Page Not Found in Web Api hosted in IIS 7

Question

I have a Web Api application. It works perfectly well when I tested it using the VS 2010 debugging dev server. But I now deployed it to IIS 7.5 and I am getting a HTTP 404 error when trying to access the application.

Here is my web.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <connectionStrings>
    <add name="DefaultConnection" connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=aspnet-FlowGearProxy-20123141219;Integrated Security=True" providerName="System.Data.SqlClient" />
  </connectionStrings>
  <appSettings>
    <add key="webpages:Version" value="2.0.0.0" />
    <add key="webpages:Enabled" value="true" />
    <add key="PreserveLoginUrl" value="true" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.0" />
    <authentication mode="Forms">
      <forms loginUrl="~/Account/Login" timeout="2880" />
    </authentication>
    <pages>
      <namespaces>
        <add namespace="System.Web.Helpers" />
        <add namespace="System.Web.Mvc" />
        <add namespace="System.Web.Mvc.Ajax" />
        <add namespace="System.Web.Mvc.Html" />
        <add namespace="System.Web.Routing" />
        <add namespace="System.Web.WebPages" />
      </namespaces>
    </pages>
  </system.web>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <modules runAllManagedModulesForAllRequests="true" />
  </system.webServer>
</configuration>

Answer 1

I also ran into this problem. I solved the problem by going to the Application Pools > Application Pool Name and changed the .NET Framework from version v.2.0.50727 to v4.0.30319.

Answer 2

Had same issue. This configuration setting solved the issue.

<system.webServer>
    .....
    <modules runAllManagedModulesForAllRequests="true" />
    .....
</system.webServer>

As explained in http://www.britishdeveloper.co.uk/2010/06/dont-use-modules-runallmanagedmodulesfo.html above solution should be avoided. Use this instead. Same solution is provided by Lopsided also. Keeping it here to let users avoid implementing the first working solution.

<modules>
  <remove name="UrlRoutingModule-4.0" />
  <add name="UrlRoutingModule-4.0" type="System.Web.Routing.UrlRoutingModule" preCondition="" />
  <!-- any other modules you want to run in MVC e.g. FormsAuthentication, Roles etc. -->
</modules>

Answer 3

A few things to check:

1. Make sure that you have the .NET Framework 4 installed.
2. Ensure that version 4 of the .NET Framework is selected for your website & virtual directory (if applicable).
3. Ensure that you have MVC installed or have the appropriate DLLs in your bin directory.
4. Might need to allow ASP.NET 4.0 web service extensions
5. Put the application in it's own app pool.
6. Make sure the directory has at least "Scripts Only" execute permissions.

Answer 4

This piece of configuration in web.config file can help as helped to me: in the system.webServer section:

      <security>
          <requestFiltering>
              <verbs applyToWebDAV="true">
                  <remove verb="PUT" />
                  <add verb="PUT" allowed="true" />
                  <remove verb="DELETE" />
                  <add verb="DELETE" allowed="true" />
                  <remove verb="PATCH" />
                  <add verb="PATCH" allowed="true" />
              </verbs>
          </requestFiltering>
      </security>      

Answer 5

I spent lot's of time trying a lot of things to finally realise I was adding my web app not in Sites/Default Web Sites, but in another website binded to another port. Obviously trying localhost on port 80 would give a 404.

Answer 6

Based on this SO answer, I just had to change path="*." to path="*" for the added ExtensionlessUrlHandler-Integrated-4.0 in configuration>system.WebServer>handlers in my web.config

Before:

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

After:

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