Orchard, WebForms and iFrames - content-management-system

Question

I am trying to embed an iFrame into a Orchard CMS section (same domain - controls live in a subdirectory off the main Orchard installation). I found two threads on here that talk about the issue I'm having (see here and here), but I'm still running into issues. The pages I am trying to load in the iFrame are standard WebForms and require both WebResource.axd and ScriptResource.axd. I managed to get WebResource.axd working, but ScriptResource is returning a 500 Internal Server Error (according to Chrome), but I can't figure out what's causing the 500 or what the real error is. The relevant entry from my web.config is below - any suggestions?
<handlers accessPolicy="Script">
<!-- clear all handlers, prevents executing code file extensions, prevents returning any file contents -->
<clear />
<!-- Custom Controls -->
<add name="ASPX" path="*.aspx" verb="*" type="System.Web.UI.PageHandlerFactory" preCondition="integratedMode" requireAccess="Script"/>
<add name="WebResource" path="WebResource.axd" verb="GET" type="System.Web.Handlers.AssemblyResourceLoader" preCondition="integratedMode" />
<add name="ScriptResource" path="ScriptResource.axd" verb="GET" type="System.Web.Handlers.ScriptResourceHandler" preCondition="integratedMode" />
<!-- Everything below added from Orchard -->
<!-- Return 404 for all requests via managed handler. The url routing handler will substitute the mvc request handler when routes match. -->
<!--<add name="NotFound" path="*" verb="*" type="System.Web.HttpNotFoundHandler" preCondition="integratedMode" requireAccess="Script" />-->
<!-- WebApi -->
<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="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" 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="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" 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="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
</handlers>

Answer 1

Combining Bertrand's suggestion and a lot of playing around, I ended up finding a solution to this.
First, the custom stuff will need to be in a subfolder and inside IIS you can switch that subfolder over to an application (not a virtual directory). For a little extra peace of mind, I also gave it a dedicated app pool so if something did get weird with it the main site wouldn't go down.
The next parts involve a couple of steps - mostly because of that <clear /> entry in system.webServer/handlers. Removing this in the parent app breaks Orchard, but having it in broke my child app since it inherits all the settings from the parent. To get around this, my child app had to have the following system.webServer configuration:
<system.webServer>
<handlers>
<remove name="NotFound" />
<add name="ASPX" path="*.aspx" verb="*" type="System.Web.UI.PageHandlerFactory" preCondition="integratedMode" requireAccess="Script"/>
<add name="WebResource" path="WebResource.axd" verb="GET" type="System.Web.Handlers.AssemblyResourceLoader" preCondition="integratedMode" />
<add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</handlers>
<modules>
<remove name="WarmupHttpModule" />
</modules>
</system.webServer>
I used the SO link referenced here to find the "real" ScriptResource.axd reference that was needed and it looks like everything is working.