Selection Item Changed Null Reference Exception

[Damon]

We recently upgraded our solution to the Q2 2010 Sp1 version and now whenever the SelectedItem or SelectedIndex of our combo boxes is changed we recieve a null reference exception with the following call stack:

   at Telerik.Windows.Controls.RadComboBoxAutomationPeer.RaiseSelectionEvents(SelectionChangedEventArgs e)

   at Telerik.Windows.Controls.RadComboBox.OnSelectionChanged(SelectionChangedEventArgs e)

   at System.Windows.Controls.Primitives.Selector.InvokeSelectionChanged(List`1 unselectedItems, List`1 selectedItems)

   at System.Windows.Controls.Primitives.Selector.SelectionChanger.End()

   at System.Windows.Controls.Primitives.Selector.SelectionChanger.SelectJustThisItem(Object item, Boolean assumeInItemsCollection)

   at System.Windows.Controls.Primitives.Selector.OnSelectedItemChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)

   at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)

   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)

   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)

   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)

   at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp)

   at System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)

   at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)

   at System.Windows.Data.BindingExpression.Activate(Object item)

   at System.Windows.Data.BindingExpression.AttachToContext(AttachAttempt attempt)

   at System.Windows.Data.BindingExpression.MS.Internal.Data.IDataBindEngineClient.AttachToContext(Boolean lastChance)

   at MS.Internal.Data.DataBindEngine.Task.Run(Boolean lastChance)

   at MS.Internal.Data.DataBindEngine.Run(Object arg)

   at MS.Internal.Data.DataBindEngine.OnLayoutUpdated(Object sender, EventArgs e)

   at System.Windows.ContextLayoutManager.fireLayoutUpdateEvent()

   at System.Windows.ContextLayoutManager.UpdateLayout()

   at System.Windows.UIElement.UpdateLayout()

   at System.Windows.Interop.HwndSource.SetLayoutSize()

   at System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)

   at System.Windows.Interop.HwndSource.set_RootVisual(Visual value)

   at System.Windows.Window.SetRootVisual()

   at System.Windows.Window.SetRootVisualAndUpdateSTC()

   at System.Windows.Window.SetupInitialState(Double requestedTop, Double requestedLeft, Double requestedWidth, Double requestedHeight)

   at System.Windows.Window.CreateSourceWindow(Boolean duringShow)

   at System.Windows.Window.CreateSourceWindowDuringShow()

   at System.Windows.Window.SafeCreateWindowDuringShow()

   at System.Windows.Window.ShowHelper(Object booleanBox)

   at System.Windows.Window.Show()

This isn't happening if we are binding to a Name/Value pair only when we are binding directly to objects and only using a DisplayMemberPath. 

Thanks for any suggestions!

[Konstantina]

Hello Damon,

Thank you for contacting us.

We are aware of this issue with RadComboBox. We are now working on it and a fix will be provided in the latest internal build this week, or next week at the latest.
Sorry for the caused inconvenience.

If you have any other questions about our controls please let us know.

Sincerely yours,
Konstantina
the Telerik team

[Damon]

Are there any known work arounds? So far not everyone on the team experiences this issue. 

[Konstantina]

Hi Damon,

Thank you for getting back to us.

The work around is to turn off the automation clients, for example the Narrator or the Audio Description from the Ease of Access Center of the Windows.

Hope this helps. If you need further help please let us know.

Greetings,
Konstantina
the Telerik team

[Damon]

The latest internal build seems to correct this issue how ever i had nothing in the ease of access center active. Is there a signed hot fix available we can use for our publishes? The unlicensed nag screen prevents us from deploying any updates.

[Konstantina]

Hi Damon,

The unlicensed screen is due to the trial version of the assemblies you are using. Once you purchase the controls and become our client, in your account will be available DEV assemblies for download, which you can use for publishing.

If you have any other questions regarding our controls please feel free to contact us again.

Regards,
Konstantina
the Telerik team

[Damon]

I have the licensed version but there is no hotfix available that is liscensed and i have no automation clients running so i can't use the paid version. I was inquiring when a hotifx would be available for download.

[Konstantina]

Hi Damon,

Could you please give us the e-mail of the license holder or tell him to contact us. In that way we will be able to add you as a developer to this license and you will be able to download DEV versions and hotfixes of our controls.

Looking forward to your reply.

Best wishes,
Konstantina
the Telerik team

[Hung]

I'm license developer and I also get the same problem with Damon. Do you have any hotfix for licence version yet?

Thanks
Hung

[Valeri Hristov]

Hello Hung,

The DEV versions of the assemblies are available for evey internal build and service pack. As for the internal builds, you just need to make sure that you have downloaded the latest official service pack under the account you use.

Kind regards,
Valeri Hristov
the Telerik team