workaround:

public class MyGridView : RadGridView
{     
    public override string ThemeClassName
    {
        get
        {
            return typeof(RadGridView).FullName;
        }
    }
 
    protected override void ProcessCodedUIMessage(ref IPCMessage request)
    {
        if (request != null) //here is the problematic point
            base.ProcessCodedUIMessage(ref request);
    }
}