aspx page won`t load in classic mode

Question

I have a website using asp.net 4.0 hosted on IIS. The website holds inside an http handler which can only be used when the application pool is in classic mode (3rd party handler). From some reason Im unable to serve my aspx page in classic mode (only in integrated mode). From what Ive read I guess the issue is in the handlers mapping so here is the list.

The error I get is 404.17 - Not Found

The requested content appears to be script and will not be served by the static file handler

Any suggestion would be much appreciated

<system.webServer>
  <handlers accessPolicy="Read, Script">
    <add name="rules-Integrated" path="*.rules" verb="*" type="System.ServiceModel.Activation.HttpHandler, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv2.0" />
    <add name="AXD-ISAPI-4.0_32bit" path="*.axd" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="PageHandlerFactory-ISAPI-4.0_32bit" path="*.aspx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="SimpleHandlerFactory-ISAPI-4.0_32bit" path="*.ashx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="WebServiceHandlerFactory-ISAPI-4.0_32bit" path="*.asmx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-rem-ISAPI-4.0_32bit" path="*.rem" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-soap-ISAPI-4.0_32bit" path="*.soap" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="svc-ISAPI-4.0_32bit" path="*.svc" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
<add name="rules-ISAPI-4.0_32bit" path="*.rules" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="xoml-ISAPI-4.0_32bit" path="*.xoml" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="xamlx-ISAPI-4.0_32bit" path="*.xamlx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="aspq-ISAPI-4.0_32bit" path="*.aspq" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="cshtm-ISAPI-4.0_32bit" path="*.cshtm" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="cshtml-ISAPI-4.0_32bit" path="*.cshtml" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="vbhtm-ISAPI-4.0_32bit" path="*.vbhtm" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="vbhtml-ISAPI-4.0_32bit" path="*.vbhtml" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
    <add name="AXD-ISAPI-4.0_64bit" path="*.axd" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="PageHandlerFactory-ISAPI-4.0_64bit" path="*.aspx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="SimpleHandlerFactory-ISAPI-4.0_64bit" path="*.ashx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="WebServiceHandlerFactory-ISAPI-4.0_64bit" path="*.asmx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-rem-ISAPI-4.0_64bit" path="*.rem" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-soap-ISAPI-4.0_64bit" path="*.soap" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="svc-ISAPI-4.0_64bit" path="*.svc" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="rules-ISAPI-4.0_64bit" path="*.rules" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="xoml-ISAPI-4.0_64bit" path="*.xoml" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="xamlx-ISAPI-4.0_64bit" path="*.xamlx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="aspq-ISAPI-4.0_64bit" path="*.aspq" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="cshtm-ISAPI-4.0_64bit" path="*.cshtm" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="cshtml-ISAPI-4.0_64bit" path="*.cshtml" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="vbhtm-ISAPI-4.0_64bit" path="*.vbhtm" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="vbhtml-ISAPI-4.0_64bit" path="*.vbhtml" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
    <add name="TraceHandler-Integrated-4.0" path="trace.axd" verb="GET,HEAD,POST,DEBUG" type="System.Web.Handlers.TraceHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="WebAdminHandler-Integrated-4.0" path="WebAdmin.axd" verb="GET,DEBUG" type="System.Web.Handlers.WebAdminHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="AssemblyResourceLoader-Integrated-4.0" path="WebResource.axd" verb="GET,DEBUG" type="System.Web.Handlers.AssemblyResourceLoader" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="PageHandlerFactory-Integrated-4.0" path="*.aspx" verb="GET,HEAD,POST,DEBUG" type="System.Web.UI.PageHandlerFactory" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="SimpleHandlerFactory-Integrated-4.0" path="*.ashx" verb="GET,HEAD,POST,DEBUG" type="System.Web.UI.SimpleHandlerFactory" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="WebServiceHandlerFactory-Integrated-4.0" path="*.asmx" verb="GET,HEAD,POST,DEBUG" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="HttpRemotingHandlerFactory-rem-Integrated-4.0" path="*.rem" verb="GET,HEAD,POST,DEBUG" type="System.Runtime.Remoting.Channels.Http.HttpRemotingHandlerFactory, System.Runtime.Remoting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="HttpRemotingHandlerFactory-soap-Integrated-4.0" path="*.soap" verb="GET,HEAD,POST,DEBUG" type="System.Runtime.Remoting.Channels.Http.HttpRemotingHandlerFactory, System.Runtime.Remoting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="svc-Integrated-4.0" path="*.svc" verb="*" type="System.ServiceModel.Activation.ServiceHttpHandlerFactory, System.ServiceModel.Activation, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="rules-Integrated-4.0" path="*.rules" verb="*" type="System.ServiceModel.Activation.ServiceHttpHandlerFactory, System.ServiceModel.Activation, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="xoml-Integrated-4.0" path="*.xoml" verb="*" type="System.ServiceModel.Activation.ServiceHttpHandlerFactory, System.ServiceModel.Activation, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="xamlx-Integrated-4.0" path="*.xamlx" verb="GET,HEAD,POST,DEBUG" type="System.Xaml.Hosting.XamlHttpHandlerFactory, System.Xaml.Hosting, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="aspq-Integrated-4.0" path="*.aspq" verb="GET,HEAD,POST,DEBUG" type="System.Web.HttpForbiddenHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="cshtm-Integrated-4.0" path="*.cshtm" verb="GET,HEAD,POST,DEBUG" type="System.Web.HttpForbiddenHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="cshtml-Integrated-4.0" path="*.cshtml" verb="GET,HEAD,POST,DEBUG" type="System.Web.HttpForbiddenHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="vbhtm-Integrated-4.0" path="*.vbhtm" verb="GET,HEAD,POST,DEBUG" type="System.Web.HttpForbiddenHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="vbhtml-Integrated-4.0" path="*.vbhtml" verb="GET,HEAD,POST,DEBUG" type="System.Web.HttpForbiddenHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="ScriptHandlerFactoryAppServices-Integrated-4.0" path="*_AppService.axd" verb="*" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="ScriptResourceIntegrated-4.0" path="ScriptResource.axd" verb="GET,HEAD" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="rules-ISAPI-2.0" path="*.rules" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" />
    <add name="rules-64-ISAPI-2.0" path="*.rules" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" />
    <add name="xoml-Integrated" path="*.xoml" verb="*" type="System.ServiceModel.Activation.HttpHandler, System.ServiceModel, Version=3.0.0.0, Culture=neutral,PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv2.0" />
    <add name="xoml-ISAPI-2.0" path="*.xoml" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" />
    <add name="xoml-64-ISAPI-2.0" path="*.xoml" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" />
    <add name="svc-ISAPI-2.0-64" path="*.svc" verb="*" modules="IsapiModule" scriptProcessor="%SystemRoot%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" />
    <add name="svc-ISAPI-2.0" path="*.svc" verb="*" modules="IsapiModule" scriptProcessor="%SystemRoot%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" />
    <add name="svc-Integrated" path="*.svc" verb="*" type="System.ServiceModel.Activation.HttpHandler, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv2.0" />
    <add name="ASPClassic" path="*.asp" verb="GET,HEAD,POST" modules="IsapiModule" scriptProcessor="%windir%\system32\inetsrv\asp.dll" resourceType="File" />
    <add name="SecurityCertificate" path="*.cer" verb="GET,HEAD,POST" modules="IsapiModule" scriptProcessor="%windir%\system32\inetsrv\asp.dll" resourceType="File" />
    <add name="ISAPI-dll" path="*.dll" verb="*" modules="IsapiModule" resourceType="File" requireAccess="Execute" allowPathInfo="true" />    <add name="TraceHandler-Integrated" path="trace.axd" verb="GET,HEAD,POST,DEBUG" type="System.Web.Handlers.TraceHandler" preCondition="integratedMode" />
    <add name="WebAdminHandler-Integrated" path="WebAdmin.axd" verb="GET,DEBUG" type="System.Web.Handlers.WebAdminHandler" preCondition="integratedMode" />
    <add name="AssemblyResourceLoader-Integrated" path="WebResource.axd" verb="GET,DEBUG" type="System.Web.Handlers.AssemblyResourceLoader" preCondition="integratedMode" />
    <add name="PageHandlerFactory-Integrated" path="*.aspx" verb="GET,HEAD,POST,DEBUG" type="System.Web.UI.PageHandlerFactory" preCondition="integratedMode" />
    <add name="SimpleHandlerFactory-Integrated" path="*.ashx" verb="GET,HEAD,POST,DEBUG" type="System.Web.UI.SimpleHandlerFactory" preCondition="integratedMode" />
    <add name="WebServiceHandlerFactory-Integrated" path="*.asmx" verb="GET,HEAD,POST,DEBUG" type="System.Web.Services.Protocols.WebServiceHandlerFactory, System.Web.Services, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" preCondition="integratedMode,runtimeVersionv2.0" />
    <add name="HttpRemotingHandlerFactory-rem-Integrated" path="*.rem" verb="GET,HEAD,POST,DEBUG" type="System.Runtime.Remoting.Channels.Http.HttpRemotingHandlerFactory, System.Runtime.Remoting, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv2.0" />
    <add name="HttpRemotingHandlerFactory-soap-Integrated" path="*.soap" verb="GET,HEAD,POST,DEBUG" type="System.Runtime.Remoting.Channels.Http.HttpRemotingHandlerFactory, System.Runtime.Remoting, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="integratedMode,runtimeVersionv2.0" />
    <add name="AXD-ISAPI-2.0" path="*.axd" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" responseBufferLimit="0" />
    <add name="PageHandlerFactory-ISAPI-2.0" path="*.aspx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" responseBufferLimit="0" />
    <add name="SimpleHandlerFactory-ISAPI-2.0" path="*.ashx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" responseBufferLimit="0" />
    <add name="WebServiceHandlerFactory-ISAPI-2.0" path="*.asmx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-rem-ISAPI-2.0" path="*.rem" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-soap-ISAPI-2.0" path="*.soap" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness32" responseBufferLimit="0" />
    <add name="AXD-ISAPI-2.0-64" path="*.axd" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" responseBufferLimit="0" />
    <add name="PageHandlerFactory-ISAPI-2.0-64" path="*.aspx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" responseBufferLimit="0" />
    <add name="SimpleHandlerFactory-ISAPI-2.0-64" path="*.ashx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" responseBufferLimit="0" />
    <add name="WebServiceHandlerFactory-ISAPI-2.0-64" path="*.asmx" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-rem-ISAPI-2.0-64" path="*.rem" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" responseBufferLimit="0" />
    <add name="HttpRemotingHandlerFactory-soap-ISAPI-2.0-64" path="*.soap" verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv2.0,bitness64" responseBufferLimit="0" />
    <add name="CGI-exe" path="*.exe" verb="*" modules="CgiModule" resourceType="File" requireAccess="Execute" allowPathInfo="true" />
    <add name="SSINC-stm" path="*.stm" verb="GET,POST" modules="ServerSideIncludeModule" resourceType="File" />
    <add name="SSINC-shtm" path="*.shtm" verb="GET,POST" modules="ServerSideIncludeModule" resourceType="File" />
    <add name="SSINC-shtml" path="*.shtml" verb="GET,POST" modules="ServerSideIncludeModule" resourceType="File" />
    <add name="TRACEVerbHandler" path="*" verb="TRACE" modules="ProtocolSupportModule" requireAccess="None" />
    <add name="OPTIONSVerbHandler" path="*" verb="OPTIONS" modules="ProtocolSupportModule" requireAccess="None" />
    <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG" modules="IsapiModule" scriptProcessor="C:\Windows\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" modules="IsapiModule" scriptProcessor="C:\Windows\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" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    <add name="ClientLoggingHandler" path="*.log" verb="POST" modules="ClientLoggingHandler" resourceType="Unspecified" requireAccess="None" />
    <add name="StaticFile" path="*" verb="*" modules="StaticFileModule,DefaultDocumentModule,DirectoryListingModule" resourceType="Either" requireAccess="Read"/>
  </handlers>
</system.webServer>

Answer 1

this answer mentions and I have confirmed in my app, and that when you configure a third party handler with the configuration "classic" in mind, the configuration must be set under <system.web><httpModules> and <system.web><httpHandlers> while for integrated it goes to <system.webServer><handlers>.

I have also a web app in asp.net 4.0 which we are using MSCaptcha (for captcha). The link i found on how to use it mentioned to use classic mode and the configuration is located inside <httpHandlers>. But, when i included the same configuration under <handlers> i could run my application in integrated mode.

So, could you try copying the configuration you have in httpHandlers regarding your third party handler to the section handlers and try to verify if the handler works in integrated mode? Rather than trying to make it work in classic mode.

Both classic and integrated support .net Framework 2.0 onwards and the framework 1.1 is only available for classic. So you could try otherwise.

Answer 2

I finally found how to solve this.

All this started because I we have a .Net 2 application already running and we needed to move gently to .Net 4. So we used the existing server and for that I needed to figure out all that is needed to add to the website in order for it to work.

I was missing both the aspx and the asmx handlers so I added them using the IIS (you can also add them in the web.config directly - the IIS is easier). I needed the aspx handlers like this:

<add name="PageHandlerFactory-ISAPI-4.0_64bit" path="*.aspx" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v4.0.3‌​0319\aspnet_isapi.dl‌​l" preCondition="integratedMode,runtimeVersionv4.0,bitness64" /> <add name="PageHandlerFactory-ISAPI-4.0_32bit" path="*.aspx" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.303‌​19\aspnet_isapi.dll" preCondition="integratedMode,runtimeVersionv4.0,bitness32" />

and the asmx handler like this:

<add name="WebServiceHandlerFactory-ISAPI-4.0" path="*.asmx" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" resourceType="Unspecified" preCondition="classicMode,runtimeVersionv4.0,bitness32" />

The reason for the asmx is that after I added the aspx handlers above I got a message "The request failed with HTTP status 405: Method Not Allowed" which was caused because my aspx page internally calls an asmx which is also hosted on the site.

Hope this helps others