After upgrading my telerik controls (wpf and reporting) to the latest sp1 release 2010.1 422 and 2010.1 423 respectively.
I'm beginning to have this error message "Object reference not set to an instance of an object." whenever i open the report file designer.
I can build and use the project dll and see the report but was not able to view the designer.
I even try to open the sample project and the same error message appears.
Any help will be appreciated.