Access WebAPI from existing WebForms domain?

I'm trying to access Asp.NET Web API using same domain that I'm use with other Web forms project.

I'm using IIS by goes to web forms project and press on Add application -> (refers to Web API) under it, and after tying to browse web API using same domain of web forms projects like this link (webFormsDomain/WebAPIAliasName/ControllerName/ActionName) I got the following error:

Stack Trace:

*[HttpException (0x80004005): Could not load type 'Intelligencia.UrlRewriter.RewriterHttpModule'.]
   System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +10053645
   System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +38
[ConfigurationErrorsException: Could not load type 'Intelligencia.UrlRewriter.RewriterHttpModule'.]
   System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +353
   System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, Boolean checkAptcaBit) +21
   System.Web.Configuration.Common.ModulesEntry.SecureGetType(String typeName, String propertyName, ConfigurationElement configElement) +39
   System.Web.Configuration.Common.ModulesEntry..ctor(String name, String typeName, String propertyName, ConfigurationElement configElement) +42
   System.Web.HttpApplication.BuildIntegratedModuleCollection(List`1 moduleList) +156
   System.Web.HttpApplication.GetModuleCollection(IntPtr appContext) +1068
   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +82
   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +173
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +218
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +296
[HttpException (0x80004005): Could not load type 'Intelligencia.UrlRewriter.RewriterHttpModule'.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +10073348
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +95
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +254*

Is this valid ?