Related objects in reportingviewer 10.0.0.0 give #error

In my VB.net apps i make use of Linq开发者_如何学Go2SQL and Reportviewer with RDLC reports. With Visual Studio 2010 they upgraded this reportviewer component so you can use the newer RDL specification from 2008. Now I've a problem to show related objects. For example assume you provide an order to the datasource of the report and then you can show something like Fields!Customer.Value.Name where Customer is a related entity.

I also got the error in my immediate window: Warning: The Value expression for the textrun ‘Name_1.Paragraphs[0].TextRuns[0]’ contains an error: The specified operation is not valid. (rsRuntimeErrorInExpression)

The problem has been reported to Microsoft here but as yet there is no solution. The only workaround appears to be exposing the required properties of the related object to the top level object.

A member of the Reporting Services team has commented on this issue and explained it's cause and why it's taken so long to get a fix. The solution has been included in VS2010 SP1, which is currently in beta.