So far we do not have any known issues regarding the vs toolbox. Could you please try to manually add the UI for Windows Phone 8 controls? Also, I want to clarify that the Telerik UI for Windows Phone 8 targets WP 8.0 and WP 8.1 Silverlight applications and it does not have RadDataGrid control. You can check our documentation to see all the supported controls : http://www.telerik.com/help/windows-phone/common-introduction.html
. In particular you can check the RadDataBoundListBox and RadJumpList controls.
In the Telerik UI for Windows Universal suite(which targets Windows 8.1 and Windows Phone 8.1 applications) the RadDataGrid is not supported for WP8.1 applications. In our next official release we will introduce a RadListView control which will be available both for WP8.1 and Windows 8.1.
Please, let me know should you need further assistance.
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