I've just wasted 4 more hours getting my simple Silverlight/WCF play area setup.
I had lots of problems and although the answers were out there on the Web they were difficult to find, especially as SL/WCF seemed to be returning bog standard exceptions every time something failed. In particular I got sick of seeing "The remote server returned an unexpected response: (404) Not Found."
So here's a list of links that you might find useful if you are planning to play with SL.
Silverlight Links for Resolving Errors
Although google search was the main way I got answers I did find these sites useful:
- Forum - Plenty of gotchas and bugs in there to catch you out, solutions to my issues were available on here though.
- Irritated Vowel - Had some answers to issues I had, including cross-domain issues when calling WCF services.
- Tim Heuer - Looks like he's got answers to lots of issues you'll have.
If you are making cross domain requests ensure you have "clientaccesspolicy.xml" and/or "crossdomain.xml" setup and be aware that the required formats of these files is different in beta 1 and beta 2.
You may also get a ProtocolException (404 not found) when you try to call a WCF service. Cross-domain calls is one reason for this but another is that your WCF service is not setup for basicHttpBinding. You can read more on the forum or in Building WCF Services For Consumption From Silverlight. This page made me realize I needed to update my service reference after changing the binding. Lastly this forum entry pointed out that for it to work you need to specify that you want it to create a Website project to host the SL app.
Oh and you will also find that when you add a "Service Reference" to the WCF service you'll find that the "ServiceReferences.ClientConfig" is incorrect.
I switched to using IIS 7 rather than the development server because I was having so many issues but to get my app within IIS7 I had to follow some of the steps here (important bit for me was setting it up for ASP.NET).
I then got an error containing the message "could not download the silverlight application". Turns out it was because the MIME type was not registered and the solution is to combine what is in this article with what is in this one (second one is more relevant).