WCF Service Error - wcf

I have a WCF service deployed on a windows 2003 server. We are using a WPF application to consume this service. The trouble is if we deploy a new version of WCF service or leave the IIS and WPF application idle for sometime and then try to execute a functionality, we are get the following exception:
The content type text/html of the response message does not match the content type of the binding (text/xml; charset=utf-8). If using a custom encoder, be sure that the IsContentTypeSupported method is implemented properly. The first 119 bytes of the response were:'<HEAD><TITLE>500: Server Error [20-0004]</TITLE></HEAD>
<BODY>
<H1>500: Server Error [20-0004]<H1>
</BODY>
</HTML>
Thanks and Regards,

A 500 error usually means there was an unhandled exception in the service. Look in the Windows event logs to see what happened.

It looks like you are creating a proxy / connection to the server, then leaving it open and using this proxy when needed.
There are two problems with this:
The problem you are getting due to timeout in periods of inactivity.
That the connection is maintained when it is not used reduces scalability.
A better way to do it is to create the proxy connection when you require it, then close / dispose of it after it gas been used. Normally I use the using statement for this.

when you get below mentioned error
500: Server Error [20-0004]
This is siteminder Web Agent error, If your website is SSO protected, then it might have Siteminder ISAPI issue with initializing.
Check Event and SSO logs.
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Related

How do I access a workflow service in silverlight?

I have one worflow service named GetDataWorkflowService.xamlx that I want to use in Silverlight.
When I add a service reference to my application, it gives a message 'This Operation is not supported for the relative URI.' It still adds the reference, however.
When I use the referece:
Servicelient proxy=new ServiceClient();
proxy.GetDataCompleted += (o, a) => Debug.WriteLine("Result is " + a.Result);
proxy.GetDataAsync(123);
I get the following error:
An error occurred while trying to make a request to URI 'http://localhost:1234/GetDataWorkflowService.xamlx'. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place, or a policy that is unsuitable for SOAP services. You may need to contact the owner of the service to publish a cross-domain policy file and to ensure it allows SOAP-related HTTP headers to be sent. This error may also be caused by using internal types in the web service proxy without using the InternalsVisibleToAttribute attribute. Please see the inner exception for more details.
I don't understand what's happening.
A few things:
What happens if you use the WCF Test Client to call GetData()? Do you get an error or does that work just fine. If you get an error here concentrate on the server parts.
What happens if you set a service reference from a console application and call your workflow service. Same error or does that work?
Is the workflow service hosted in the same web site as the Silverlight client? If not do you have the cross domain policy files setup correctly.
Assuming the WCF Test Client works. Open up fiddler and compare the request from your Silverlight client with that from the WCF Test Client. What is different?
Enable tracing on the server to see if there are any exceptions or warnings that might provide more insight to what is wrong.
Check your startup project to be sure you are starting a web project and not the Silverlight project. For more details see Troubleshooting Workflow Services / Silverlight on my blog

Getting a MethodAccessException(in event log of server) and HTTP Error 401 Unauthorized(at client side) in WCF Rest Service in IIS6.0 Win2K3 enviorn

I wrote a WCF REST based service that uses webHttpBinding and uses JSON to post data.This service works fine in all of our internal environments. But in one of our environment which is exact replica of Production. It is not working. If I inspect in Firebug, I see "HTTP Error 401 Unauthorized" and in server I See following in the event log.
System.MethodAccessException
System.ServiceModel.Activation.HostedHttpRequestAsyncResult.ExecuteSynchronous
MethodAccessException: System.ServiceModel.Activation.HostedHttpRequestAsyncResult.ExecuteSynchronous(System.Web.HttpApplication, Boolean) at System.ServiceModel.Activation.HttpHandler.ProcessRequest(HttpContext context)
I haven't pasted the whole event log. But,afore are the key parts of it.
I am not able to figure out what is happening, we are using custom httpmodule for authentication.
Need urgent help on this
Thanks in advance
From MSDN, a MethodAccessException occurs when you try to call a private/protected method from somewhere that you aren't allowed. This is thrown during reflection, which is more than likely what WCF is doing under the covers.
My bet is that one of your service methods is marked as private or protected.
This would work in your local environment because it's under Full Trust. Your production environment is most likely running in Medium Trust. (Under Medium Trust, you aren't allowed to bypass the accessibility modifiers.)
-- Tatham

wcf service stops after few requests

I am working on an application where i am using a wcf service. I am currently hosting my service on localhost and accessing it from there only by adding the service reference in my project. On one of my page i am sending request on change of selected index on dropdown list. It works fine for first few requests but suddenly stops after that giving following excsption
"Failed to invoke the service. Possible causes: The service is offline or inaccessible; the client-side configuration does not match the proxy; the existing proxy is invalid. Refer to the stack trace for more detail. You can try to recover by starting a new proxy, restoring to default configuration, or refreshing the service."
How can service stop without any reason and that too from my localhost. It only works for first 3-4 requests. In service i am just sending a integer and getting back the records on its basis using a class in a generic list.
Thanks in advance
What protocol / bindings are you using? Can you show us the config? Anything inside the <system.serviceModel> on both the server and the client side.
Do you maybe create a client proxy and call the service method and not properly close and dispose of the client proxy? In that case, you might run out of connections at some point - but that's next to impossible to tell without some code to see what you're doing. Can you show us the service contract in question, and the code how you call it from the client side?

How to diagnose client-side WCF issues in Silverlight environment?

It seems that WCF diagnostics is not available in SL. Is it because of limited System.Diagnostics support or something else? Anyway, how do you track client-side WCF issues when server-side diagnostics is not enough?
This is how I solved my problem of correctly obtaining exceptions at the Silverlight Client. Similar to Rus' but does not require wrapping of exceptions. Though it does require the version number to be exact in web.config (still working on solving that)
Programmatic configuration of Exception-sending in WCF
I think this article will help.
http://msmvps.com/blogs/theproblemsolver/archive/2009/01/27/returning-exception-information-to-a-silverlight-client-through-wcf.aspx
If you're getting a 'Not Found' Error the most likely cause is the cross domain access policy. What I use to try diagnose those problems is Fiddler2, and look at the raw traffic.
Are you sure that your WCF service is not faulting on the call? If something is going wrong on the server-side the returned message will be of HTTP status code 500. Due to security restrictions, the browser will not pass any non-200 messages back to the silverlight plugin which results in silverlight throwing the classic CommunicationException "The remote server returned an error: NotFound."
There are some pretty well documented work-arounds for using a WCF behavior to change the HTTP status code on the fault from 500 to 200 so silverlight will actually have access to the details of what went wrong. More info here:
http://msdn.microsoft.com/en-us/library/dd470096(VS.95).aspx
http://www.netfxharmonics.com/2009/07/Understanding-WCF-Faults-in-Silverlight-3

Silverlight WCF calls work in IE but not in FF

I'm having a WCF service deployed on one of my servers, and my Silverlight app on the other server. The problem I'm having is running it in Firefox 3.5. Opening in IE 6/7 works great, but when I open it in Firefox it loads the app, but on calling WCF service i get this:
An error occurred while trying to make a request to URI 'http://10.1.1.20:87/MyService.svc'. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place, or a policy that is unsuitable for SOAP services. You may need to contact the owner of the service to publish a cross-domain policy file and to ensure it allows SOAP-related HTTP headers to be sent.
(The connection works over VPN so don't worry about the IP address)
I have encountered a similar problem and after a lot of research I found that adding the following line of code into the constructor of my UserControl solved the problem:
bool registerResult = WebRequest.RegisterPrefix("http://", WebRequestCreator.BrowserHttp);
More information about the WebRequest member can be found here.