How to fix the NullReferenceException when creating a component by dragging its icon from the Toolbox

This error is caused by the fact the GridControl icon on the Toolbox refers to a non-existing assembly. Please select the GridControl icon in the Toolbox and press the Delete key to delete it. Then right-click the Toolbox, select Add/Remove Items..., and then select the GridControl component in the list of available .NET components. If you have the DXperience components installed, you can use the ToolboxCreator to recreate toolbox icons: close Visual Studio and launch the ToolboxCreator from Start Menu\Programs\Developer Express .NET 2005 v6.1\Tools.

See Also:
Component designers are unavailable. Components are not displayed on forms in design mode
Troubleshooting design-time problems
A138
What information do you need to fix a problem, which occurs with your products at design time?
How to resolve the design-time problem when opening forms in Visual Studio 2005 after updating DevExpress controls