We have a issue where we are opening a grid. We have overridden the grid_AfterSortChange event where we are running the following code:

Private Sub grid_AfterSortChange(ByVal sender As Object, ByVal e As BandEventArgs) Handles MyBase.AfterSortChange
     ' Is grid setting requires it, perpetuate sortedcloumns down the bands
     Try
 
         If Me.IsUpdating Then Exit Sub
 
         If Me._bCascadeSorting AndAlso e.Band.Index = 0 AndAlso Me.DisplayLayout.Bands.Count > 1 Then
             For i As Integer = 1 To Me.DisplayLayout.Bands.Count - 1
                 With Me.DisplayLayout.Bands(i)
                     .SortedColumns.Clear()
                     For Each col As UltraGridColumn In e.Band.SortedColumns
                         If Not col.IsGroupByColumn AndAlso .Columns.Exists(col.Key) Then
                             .SortedColumns.Add(col.Key, col.SortIndicator = SortIndicator.Descending)
                         End If
                     Next
                 End With
             Next
         End If

However at the point we call Me.DisplayLayoput.Bands(i).SortedColumns.Clear() we get the following stack trace:

Error in tfUltraGrid_AfterSortChange.: Cannot access a disposed object.
Object name: 'Infragistics.Win.UltraWinGrid.UltraGridColumn'.

Exception StackTrace:

at Infragistics.Shared.DisposableObject.VerifyNotDisposed()
at Infragistics.Shared.SubObjectBase.NotifyPropChange(PropChangeInfo trigger)
at Infragistics.Win.UltraWinGrid.UltraGridColumn.InternalSetSortIndicator(SortIndicator sortIdicator)
at Infragistics.Win.UltraWinGrid.SortedColumnsCollection.InternalClear()
at Infragistics.Win.UltraWinGrid.SortedColumnsCollection.ApplyNewSortedColumns(SortedColumnsCollection newSortedColumns, Boolean groupBy)
at Infragistics.Win.UltraWinGrid.SortedColumnsCollection.ProcessNewSortedColumnsHelper(SortedColumnsCollection newSortedColumns, Boolean fireEvents, Boolean groupBy)
at Infragistics.Win.UltraWinGrid.SortedColumnsCollection.Clear()
at thinkFolio.tFUltraGrid.grid_AfterSortChange(Object sender, BandEventArgs e)

Is there any particular reason we would be getting this error as it suggestions that we are trying to access a grid column that has been disposed. We are only opening a grid view.