Calling a https WCF-Service from Silverlight 4 only works with fiddler and from VS2010

Question

for days now, I try to get the following scenario running:

I have a Silverlight 4 Application that calls a WCF-Service via HTTPS. The WCF-Service is located on one of our servers, the Silverlight 4 app is also served from this server. After several hours of trial and error (well actually more error than try) I get it running when starting it from my VS2010 development environment on my local machine (see also SecurityError when calling a HTTPS-WCF Service from Silverlight 4 ).

But ...

The call to the https-WCF ONLY works when I start the SL-App from my VS2010 AND when fiddler is running and after I tell fiddler to ignore the Certificate Error (I use a self-signed certificate). When fiddler is not running, I get a security error. That applies, when my browser is the IE. When I copy the localhost address from the IE and paste it in my opera, it works without fiddler.
When I deploy the Silverlight app to the server and call it from the server, the WCF-call doesn't work, whether fiddler is running or not. I just get the standard Message, that an exception has occurred. This happens in both Opera and IE. Fiddler doesn't ask me to ignore the Certificate Error like it does in the VS2010 scenario, so maybe there is somewhere the key to my problem. Unfortunately, I have not much experiences with this stuff, so I have no idea, where to look or what to do.

I already found something about the fiddler issue here on stackoverflow ( Silverlight Requests, Failures & Fiddler ), but it doesn't help me solving my problem.

I hope that some of you can shed some light in this issue, before all my hair is turned to gray.

Thanks in advance,
Frank

Edith has just installed the Certificate as a trusted Certificate in IE - but I still get the error, when calling the WCF when starting the deployed silverlight app from the server. At least I can call the Service when I start the SL app from VS2010 in the IE now (even when that doesn't help me, when some one else has to work with the app.

Answer 1

Several thoughts:

• What is the exact error message you're seeing? Any inner exceptions?

• Could this be a cross-domain issue? (Are the Silverlight XAP and the WCF service hosted from exactly the same domain, including its HTTP vs HTTPS characteristic, port number, distinction between "localhost" and an actual machine name, etc? What is the exact address as it appears in ServiceReference.ClientConfig or in code, and does its domain name exactly match the XAP's domain name?)

• Do you see any call attempting to go through in Fiddler at all when it fails? (If not, I would strongly suspect a cross-domain issue)

• If you manually browse to the https://....../YourService.svc from IE/Opera (instead of invoking the service through code in Silverlight), can you successfully see the service information page, with no certificate warnings/errors?

Answer 2

Does your SSL certificate has the same name as your service host? If not, that causes an error which can lead to the described behavior