M@rkJakes.com

Sometimes I kick myself for not checking out 'Breaking Changes' when upgrading from one version of a product to another and Silverlight is no different.

When upgrading one of my projects from Silverlight 3 to Silverlight 4 I kept getting

"The type or namespace name 'ria' does not exist in the namespace 'system.windows'"

If you are getting this, the solution is quite simple, RTFM  :-)    Go to

Here you will find in the documentation that 'System.Windows.Ria' has been depreciated.

In your Silverlight 4 client, simply change your 'using' statement from ...

using System.Windows.Ria;

To...

using System.ServiceModel.DomainServices.Client;