Error 404 - file not found on Silverlight RIA service call - silverlight-4.0

Question

I have search everywhere for a solution to my problem, but I am not able to find one. I have built a Silverlight 4 Navigation app, and am using RIA Services to process a custom entity (which is essentially running server-side calls to COM dlls). In my debug environment, everything works fine, but when I try to deploy to IIS7 (on the development machine) as a website, it gives me the following error when calling the Get query on the entity:
Load operation failed for query 'GetNewHWCoil'. The remote server returned an error: NotFound.
at System.ServiceModel.DomainServices.Client.OperationBase.Complete(Exception error)
at System.ServiceModel.DomainServices.Client.LoadOperation.Complete(Exception error)
at System.ServiceModel.DomainServices.Client.DomainContext.CompleteLoad(IAsyncResult asyncResult)
at System.ServiceModel.DomainServices.Client.DomainContext.<>c__DisplayClass1b.<Load>b__17(Object )
Everything I found online says to check the Authentication area on IIS and make sure that it is set only to Anonymous Authentication, which it is. And they also say to enable WCF logging, which when I add the necessary text to the web.config file, I still don't get any logs. They also say to use Fiddler2 to trace the HTTP calls, but I only get a 404 error on there with the textview giving me the standard IIS file not found website. I cannot figure out how to debug this problem.
The Silverlight app needs to make calls to a set of 3rd party COM dlls to calculate the performace of water coils. Since I do not want to have the app run OOB, (this will negate the whole point of it being a web app instead of a WPF app) I have the ASP.net project interacting with the dlls using the custom entities.
The function (or Query as RIA services calls it) GetNewHWCoil is located in the DomainService class and uses this code:
Public Function GetNewHWCoil() as HWCoil 'HWCoil is a custom object
If bRanCalc then 'bRanCalc is a global boolean variable that gets set to true if the calc call on the dlls have been made
Return mHWCoil 'global copy of the calculated coil object
bRanCalc = False
else
Return New HWCoil
end if
End Function
The error runs before any calculation should be called, so it is assumed that it is erroring on the 'Return New HWCoil' part.
Any help on this would be appreciated.
Thanks,
Chris

Answer 1

I found the solution to my problem. I fonud out that I can have VS run the debug from IIS, and when I had it create the virtual directory it told me I needed to install ASP.NET 4 on the server. I thought that by checking the ASP.NET checkbox in the Add Windows Features dialog that I had already done that. But it only installed .NET 2 version. So after looking online for this new problem, I found that I needed to run the command
C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis -i
and everything worked fine after that.
Chris