ASP.NET Web API application gives 404 when deployed at IIS 7

I have an ASP.NET Web API which works fine when running on "IIS Express" with localhost:1783

Settings in VS

But when I uncross the "Use IIS Express" and then press "Create Virtual Directory"...

New settings

...I just get 404 errors: The 404 error

Any ideas whats wrong? Thanks!

Solution 1:

While the marked answer gets it working, all you really need to add to the webconfig is:

    <handlers>
      <!-- Your other remove tags-->
      <remove name="UrlRoutingModule-4.0"/>
      <!-- Your other add tags-->
      <add name="UrlRoutingModule-4.0" path="*" verb="*" type="System.Web.Routing.UrlRoutingModule" preCondition=""/>
    </handlers>

Note that none of those have a particular order, though you want your removes before your adds.

The reason that we end up getting a 404 is because the Url Routing Module only kicks in for the root of the website in IIS. By adding the module to this application's config, we're having the module to run under this application's path (your subdirectory path), and the routing module kicks in.

Solution 2:

For me, in addition to having runAllManagedModulesForAllRequests="true" I also had to edit the "path" attribute below. Previously my path attribute was "*." which means it only executed on url's containing a dot character. However, my application's url's don't contain a dot. When I switched path to "*" then it worked. Here's what I have now:

  <system.webServer>
      <validation validateIntegratedModeConfiguration="false" />
      <modules runAllManagedModulesForAllRequests="true">
      <remove name="WebDAVModule"/>
      </modules>

      <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="*" 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="*" 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="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
      </handlers>
  </system.webServer>

Solution 3:

You may need to install Hotfix KB980368.

This article describes a update that enables certain Internet Information Services (IIS) 7.0 or IIS 7.5 handlers to handle requests whose URLs do not end with a period. Specifically, these handlers are mapped to "." request paths. Currently, a handler that is mapped to a "." request path handles only requests whose URLs end with a period. For example, the handler handles only requests whose URLs resemble the following URL:

http://www.example.com/ExampleSite/ExampleFile.

After you apply this update, handlers that are mapped to a "*." request path can handle requests whose URLs end with a period and requests whose URLs do not end with a period. For example, the handler can now handle requests that resemble the following URLs:

http://www.example.com/ExampleSite/ExampleFile

http://www.example.com/ExampleSite/ExampleFile.

After this patch is applied, ASP.NET 4 applications can handle requests for extensionless URLs. Therefore, managed HttpModules that run prior to handler execution will run. In some cases, the HttpModules can return errors for extensionless URLs. For example, an HttpModule that was written to expect only .aspx requests may now return errors when it tries to access the HttpContext.Session property.

Solution 4:

This issue can also happen due to the following

1.In the Web.Config

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

2.Make sure the following are available in the bin folder on the server where the Web API is deployed

•System.Net.Http

•System.Net.Http.Formatting

•System.Web.Http.WebHost

•System.Web.Http

These assemblies won't be copied in the bin folder by default if the publish is through Visual Studio because the Web API packages are installed through Nuget in the development machine. Still if you want to achieve these files to be available as part of Visual Studio publish then you need to set CopyLocal to True for these Assemblies

Solution 5:

Some people say runAllManagedModulesForAllRequests="true" will have performance issues and MVC routing issues. They suggest to use the following:

http://www.britishdeveloper.co.uk/2010/06/dont-use-modules-runallmanagedmodulesfo.html

http://bartwullems.blogspot.com/2012/06/optimize-performance-of-your-web.html