i'm getting a randomly occurring exception when extensively scrolling through the grid that is grouped on 3 or more columns.
The grid is bound to a source with ca 600 records, other properties are:
SelectedItem="{Binding SelectedItem, Mode=TwoWay}"
AutoGenerateColumns="False"
CanUserDeleteRows="False"
CanUserInsertRows="False"
DataLoadMode="Asynchronous"
IsFilteringAllowed="True"
IsReadOnly="True"
ScrollMode="RealTime"
ShowGroupPanel="True"
ShowInsertRow="False"
SelectionMode="Extended"
EnableColumnVirtualization="true"
EnableRowVirtualization="True"
ItemsSource="{Binding WorkItems}"
local:GridViewHeaderMenu.IsEnabled="false"
UserLayouts="{Binding UserLayouts}"
ShowColumnFooters="False"
ShowGroupFooters="False"
IsQuickFilterRowEnabled="True"
IsSynchronizedWithCurrentItem="True"
SelectionUnit="FullRow">
After I grouped by say 4 or 5 columns, I expand some groups and start scrolling the grid using mouse or page up/ page down keys. If I keep doing that for a 1-2 minutes, I am eventually getting a NullReferenceException from Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.get_LayoutStrategy():
Message: Unhandled Error in Silverlight Application [Arg_NullReferenceException]
Arguments:
Debugging resource strings are unavailable. Often the key and arguments provide sufficient information to diagnose the problem. See http://go.microsoft.com/fwlink/?linkid=106663&Version=5.0.10411.00&File=mscorlib.dll&Key=Arg_NullReferenceException at Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.get_LayoutStrategy()
at Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.SubscribeToGeneratorEvents()
at Telerik.Windows.Controls.GridView.GridViewBaseVirtualizingPanel.OnLoaded(Object sender, RoutedEventArgs e)
at MS.Internal.CoreInvokeHandler.InvokeEventHandler(UInt32 typeIndex, Delegate handlerDelegate, Object sender, Object args)
at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName, UInt32 flags)
Line: 1
any ideas on what's causing it and how to fix?