DatePicker under IE 9 and SL 5 crashes

[Masoud]

Hi there,

this is the configuration of on of the pcs we are testing our software on:

Windows 7 Professional SP1
IE 9.0.8112.16421
Silverlight Version: 5.0.61118.0 

When the DatePicker is klicked, I get the message, "IE has stopped running...".  Could you please test this scenario?

Best regards

[Georgi]

Hello Klaus,

I have tested this scenario, but I wasn't able to reproduce the crush. I am sending you a video of what i am doing. Can you confirm that you are doing the same thing? Maybe you have more complicated project than just one DatePicker, if so a simple project would be appreciated. Also If you can capture the stack trace or the exception could be helpful.

Regards,
Georgi
the Telerik team

[Masoud]

Hello Georgi,

it turns out that the crashes occured using the following combination:
- Silverllight App ist SL 4.0
- Dev Machine had SL5 Runtime and SDK
- Using Telerik 2011Q3
- Browser had SL 5 installiert.

The crash was a AccessViolationException that occured when the page in the pager was changed (not the first load).  

I changed the configurations to
- Silverllight App ist SL 5.0
- Dev Machine had SL5 Runtime and SDK and Toolkit
- Using Telerik 2012Q1
- Browser had SL 5 installiert.

and all is working fine!

Thank you for your effort.



Thank you for your effort.

[Masoud]

Hello Georgi,

the problem still persists and I was able to narrow down the conditions that cause the browser to crash with an AccessViolationExcpetion and no stack trace (in VS it's null, please see the attached VS screen shot).  

Microsoft Windows 6.1.7601
PC language German
Silverlight 5.1.10411.0 
Internet Explorer 9.0.8112.16421
Firefox 12.0
Google Chrome 19.0.1084.52 

The issue doesn't occur when selecting a date, only when selecting a month or a year.  Following please find an example of markup that causes the exception.

Culture="de-DE" DisplayFormat="Short" InputMode="DatePicker" SelectedValue="{Binding Path=Current.Pflzjahr, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}" DateSelectionMode="Year" Width="80" BorderBrush="Black" DateTimeWatermarkContent="" Margin="0,0,5,0" VerticalAlignment="Center" Height="25"

This is a very troubling issue for our application as there are plenty of points where users will not input a full date, but a portion, i.e. month or year.  

Thank you for your effort.

[Georgi]

Hello Klaus,

I still wasn't able to reproduce the issue. Can you please check the attached project and let us now if we are doing the same thing here?  If not a simple project, where it can be reproduced would be very helpful.
As you can see in the attached screenshot I am using :

Microsoft Windows 6.1.7601
PC language German
Silverlight 5.1.10411.0
Firefox 12.0


Greetings,
Georgi
the Telerik team

[Masoud]

Hello Georgi,

the exception occurs with your project as well.  Please find attached a screenshot of IE crashing.  The problem occurs on a couple of test pcs (one is a Windows 7 tablet).  I will have to run Visual Studio on the pc and reference the VS Projects of the Telerik controls, and hope that I can provide you with a more meaningful stacktrace.

Thank you for your effort!

[Georgi]

Hello Klaus,

Can you confirm that you are using 2011.3.1116.1040 version of the Telerik Controls? Also what comes in mind is are you using Silverlight 4 or Silverlight 5 project? Also I have attached a video just to make sure that we are doing the same thing.


Kind regards,
Georgi
the Telerik team

[Masoud]

Hello Georgi,

we are using 2012.1.0430.1050.  The app is written against Silverlight 5.  I will check the video on Monday, and make a video of our test pc and send it to you.

Best regards

[Georgi]

Hi Klaus,

I have recorded another video using  2012.1.0430.1050, but still wasn't able to reproduce it. I am looking forward to your video.

All the best,
Georgi
the Telerik team

[Masoud]

Hi Georgi,

I finally managed to reference Telerik's own VS projects and have reproduced the behavior that freezes IE/FF/Chrome:

The Exception is a AccessViolationException.

    [External Code]
>   Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadCalendar.PopulateYears() Line 3432 + 0x11 bytes  C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadCalendar.UpdateCalendarViews() Line 3641 + 0x8 bytes C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadCalendar.OnDisplayDateChanged(System.Windows.DependencyObject sender = {Telerik.Windows.Controls.RadCalendar}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) Line 3028 + 0xe bytes  C#
    Telerik.Windows.Controls!Telerik.Windows.PropertyMetadata.PropertyChangeHook.OnPropertyChanged(System.Windows.DependencyObject d = {Telerik.Windows.Controls.RadCalendar}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) Line 340 + 0x34 bytes C#
    [External Code]
    BindingDebugging!DateTimePickerxaml_6.BindingOperation_1420_59(object BindingState = {System.Windows.Data.Debugging.BindingDebugState}) Line 1 + 0x11 bytes Unknown
    [External Code]
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.DisplayDate.set(System.DateTime value = {System.DateTime}) Line 586 + 0x39 bytes  C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.OnSelectedValueChanged() Line 1320 + 0xfe bytes   C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.OnSelectedValueChanged(System.Windows.DependencyObject d = {Telerik.Windows.Controls.RadDatePicker}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) Line 1126 + 0xe bytes C#
    Telerik.Windows.Controls!Telerik.Windows.PropertyMetadata.PropertyChangeHook.OnPropertyChanged(System.Windows.DependencyObject d = {Telerik.Windows.Controls.RadDatePicker}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) Line 262 + 0x34 bytes   C#
    [External Code]
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.SelectedValue.set(System.DateTime? value = {System.DateTime}) Line 474 + 0x29 bytes   C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.MergeSelectedValue() Line 1394 + 0x128 bytes  C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.OnSelectedDateChanged() Line 1368 + 0x8 bytes C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadDateTimePicker.OnSelectedDateChanged(System.Windows.DependencyObject d = {Telerik.Windows.Controls.RadDatePicker}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) Line 1132 + 0x3d bytes C#
    Telerik.Windows.Controls!Telerik.Windows.PropertyMetadata.PropertyChangeHook.OnPropertyChanged(System.Windows.DependencyObject d = {Telerik.Windows.Controls.RadDatePicker}, System.Windows.DependencyPropertyChangedEventArgs e = {System.Windows.DependencyPropertyChangedEventArgs}) Line 262 + 0x34 bytes   C#
    [External Code]
    BindingDebugging!DateTimePickerxaml_9.BindingOperation_1423_60(object BindingState = {System.Windows.Data.Debugging.BindingDebugState}) Line 1 + 0x11 bytes Unknown
    [External Code]
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadCalendar.SelectedDate.set(System.DateTime? value = {System.DateTime}) Line 837 + 0x21 bytes  C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.RadCalendar.Select(System.DateTime selectedDate = {System.DateTime}, bool forceSelection = true) Line 2380 + 0x5d bytes C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.Calendar.CalendarView.AddDateToCalendarSelection(Telerik.Windows.Controls.Calendar.CalendarButtonContent content = {Telerik.Windows.Controls.Calendar.CalendarButtonContent}) Line 526 + 0x40 bytes C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.Calendar.CalendarView.AddDate(object sender = {Telerik.Windows.Controls.Calendar.CalendarButton}) Line 514 + 0xb bytes  C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.Calendar.CalendarView.HandleMouseEvents(object sender = {Telerik.Windows.Controls.Calendar.CalendarButton}, System.Windows.Input.MouseButtonEventArgs e = {System.Windows.Input.MouseButtonEventArgs}) Line 446 + 0x15 bytes    C#
    Telerik.Windows.Controls.Input!Telerik.Windows.Controls.Calendar.CalendarView.CalendarButtonMouseLeftButtonDown(object sender = {Telerik.Windows.Controls.Calendar.CalendarButton}, System.Windows.Input.MouseButtonEventArgs e = {System.Windows.Input.MouseButtonEventArgs}) Line 433 + 0x12 bytes    C#
    [External Code]

The failure occurs when I change the date in the datepicker.

Following is the markup of the RadDatePicker :

<RadInput:RadDatePicker x:Name="PflanzJahr" Culture="de-DE" DisplayFormat="Short" InputMode="DatePicker" SelectedValue="{Binding Path=Current.Pflzjahr, Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}" DateSelectionMode="Year" Width="80" IsEnabled="{Binding Path=BearbeitenIsEnabled}" BorderBrush="Black" DateTimeWatermarkContent="Jahr" Margin="0,0,5,0" VerticalAlignment="Center" Height="25" />

Thank you very much for your effort helping on this issue! 

[Masoud]

Hi Georgi,

I just noticed that the exception is not thrown if I put a breakpoint on the statement 

calItemsControl.ItemsSource = itemsSource;

Line 3432 in Controls\Input\Calendar\RadCalendar.cs.  If I remove the breakpoint, the exception occurs.

Setting the year using the textbox part of the RadDatePicker runs without an exception also.  The issue is related to the PopUp with the years.  

If you need further tests using styles, themes, etc. I would be glad to provide you with the data needed.

Best 

[Georgi]

Hi Klaus,

I did some more research on this exception and found out a lot of helpful information in this forum thread. So as you can see the issue comes from the Silverlight itself. Nevertheless here you can find some suggestions for a workaround - changing the RadWaterMarkTextBox with a simple TextBox seems to fixes the issue. Also here you can see that according to Microsoft the issue is fixed with the latest Silverlight release. It would be great if you can try some of the suggested workarounds  and let us know if it works for you.

All the best,
Georgi
the Telerik team

[Shaun]

I am having this problem with the most simple of configurations.

<telerik:RadDatePicker Width="125" DateSelectionMode="Month"  />

Choosing a month then crashes the application with a NullReferenceException:

   at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
   at MS.Internal.XcpImports.SetValue(IManagedPeerBase obj, DependencyProperty property, Boolean b)
   at System.Windows.DependencyObject.SetValue(DependencyProperty property, Boolean b)
   at System.Windows.Controls.ItemsControl.ClearContainers(Boolean bHostIsReplaced)
   at System.Windows.Controls.ItemsControl.ItemsSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
   at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
   at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet, Boolean isBindingInStyleSetter)
   at System.Windows.Controls.ItemsControl.set_ItemsSource(IEnumerable value)
   at Telerik.Windows.Controls.RadCalendar.PopulateMonths()
   at Telerik.Windows.Controls.RadCalendar.UpdateCalendarViews()
   at Telerik.Windows.Controls.RadCalendar.OnDisplayDateChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
   at Telerik.Windows.PropertyMetadata.PropertyChangeHook.OnPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
   at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
   at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet, Boolean isBindingInStyleSetter)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.RadCalendar.set_DisplayDate(DateTime value)
   at Telerik.Windows.Controls.RadCalendar.OnSelectedDateChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
   at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
   at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet, Boolean isBindingInStyleSetter)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.RadCalendar.set_SelectedDate(Nullable`1 value)
   at Telerik.Windows.Controls.RadCalendar.Select(DateTime selectedDate, Boolean forceSelection)
   at Telerik.Windows.Controls.Calendar.CalendarView.AddDateToCalendarSelection(CalendarButtonContent content)
   at Telerik.Windows.Controls.Calendar.CalendarView.AddDate(Object sender)
   at Telerik.Windows.Controls.Calendar.CalendarView.HandleMouseEvents(Object sender, MouseButtonEventArgs e)
   at Telerik.Windows.Controls.Calendar.CalendarView.CalendarButtonMouseLeftButtonDown(Object sender, MouseButtonEventArgs 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)

I am using 2012.1.326.1050

[Shaun]

And *I believe* this problem is easily replicated on the telerik demo site as well:

http://demos.telerik.com/silverlight/#DateTimePicker/Configurator

Simply change "DateSelectionMode" to Month, and pick a month.    For me, the control simply doesnt work in Month selection mode. ( Perhaps a similar exception is being caught and ignored.),  and frequently crashes as well.

[Masoud]

Hi Georgi,

You suggest upgrading to the lastest Silverlight runtime.  All PCs we test against are running runtime 5.1.10411.0.

Could you please provide me with a project that shows how to exchange the RadWaterMarkTextBox with a simple TextBox?  I would then test this change and give you feedback on this issue.

Link suggests using UpdateLayout().  I would need to do this in Telerik's own code, meaning that I would have to maintain my own copy of the code base.  Could you not add this to your code base?  I cannot afford to maintain my own codebase for Telerik controls!

The replies provided by Shaun below show that the issue is not limited to the test PCs I have.  Under certain conditions RadDatePicker (2012.1.0430.1050) running against runtime 5.1.10411.0 throws a critical exception and crashes the browser.  I know that this is the nightmare of developers: an bug that shows on some but not other PCs.  I and others faced with this issue need a statement from you! Is Telerik interested in solving this issue or not?  I would be happy to provide Telerik with all the information needed to solve this issue. We are unable to release UI to our users with the RadDatePicker (selecting months or years), since we don't know if the PCs of the users will "tolerate" the control or not.  In case this turns to be "unsolvable" (which I really hope is not the case) please make this known so that developers would have a choice.

Thank you very much for your effort on this!

Best regards 

[Masoud]

Hi Shaun,

are you using any styles/templates with the RadDatePicker or do you crash the browser with the plain RadDatePicker?

Best 

[Shaun]

No styles/templates or anything.

1) new project, reference Telerik.Windows.Controls and Telerik.Windows.Controls.Input 2012 Q1
2) Add DatePicker control with DateSelectionMode set to month

<telerik:RadDatePicker Width="125" Height="40" DateSelectionMode="Month"  />

3) Run.  Crash.

I have no other PCs to test it out on right now.

[Shaun]

Klaus, can you post the specs for the PC(s) which show the error behavior?

[Masoud]

Hi Shaun,

the specs are
Microsoft Windows 6.1.7601
PC language German 
Silverlight 5.1.10411.0
Firefox 12.0 


Georgi from Telerik has already done the testing with a Test PC based on the specs and he was unable to reproduce the results.  

Best

[Shaun]

How about hardware specs?  The machines we are having the issue on are ThinkPad510 w/ 12 GB ram (64 bit win 7). 

Some of my early theories were that it may be related to having larger amounts of ram, having had installed VMWare, or possibly silverlight development tools (or some combination).  Can you rule any of these out?

Also, (and this is a bit random and possibly off topic) can you check to see if the PCs you are having the problem on also exhibit the behavior I outline here:  http://stackoverflow.com/questions/10644315/silverlight-mvvm-bindings-memory-leaks ?   (there is a hosted silverlight example along with instructions on testing whether the problem effects that pc)

There could be some relationship...  That is, silverlight may simply be untrustworthy / unreliable under certain hardware/software configurations which I've yet to pinpoint.

[Masoud]

Hi Shaun,

it's great to know that I am not alone with this issue!

The PCs where RadDatePicker freezes the browser are the ones where your test fails (Garbage Collection is failing).  The dev PC I work on passes the test (10 MB regardless of how often I create new views) and can handle a RadDatePicker.  Your guess about a possible connection was right!

My Dev PC is Lenovo T510 with 8 GB RAM and running VMware.  I cannot reproduce the issue on it, neither on the host,, nor on the guests (VMWare).

I cannot tell how the two issues are can be related.  I can confirm, however, that PCs that fail the GC test also are unable to run the RadDatePicker.  Your test, should help the people at Telerik solving the issue.  Using your test, one can determine beforehand if a PC will reproduce the error or not.  

I will wait for Georgi until next week and ask him if a support ticket should be submitted.  I am sure that Telerik will be interested in clearing this situation and that they have the capacity to do a thorough investigation of the issue!

Best

[Shaun]

Thanks for the information Klaus.

I think the memory leak issue is the bigger problem here.  I can find other ways to provide datepicker support, but the memory leak issue is a performance nightmare which makes silverlight as a platform virtually unusable for this subset of PCs which exhibit the behavior.

It's frustrating not knowing how wide-spread the problem is, and exceedingly difficult to solicit support from MS (or anyone else) since it seems to be PC specific.

[Shaun]

Klaus,

I believe I have precisely identified the problem.  Now we just need to come up with a good solution.  Let me explain.

First, I dove deeper into the memory-leak issue and used the redgate memory profiler.    Here is the output showing the reference chain which illustrates the problem:

http://tinypic.com/r/2lwlpc8/6

I had been here before, but this time I focused in on that TextBoxAutomationPeer.  Googling wasn't very helpful, until I searched for "AutomationPeer Memory Leak" and came upon this article, which is well worth reading:

http://www.wintellect.com/cs/blogs/sloscialo/archive/2011/04/13/silverlight-memory-leaks-and-automationpeers.aspx

Sure enough, as soon as i went to my services and stopped the "Tablet PC Input Service", the memory leak went away.   And, believe it or not, the DatePicker functions correcty!

So, what we can conclude is that any PC which triggers silverlight automation via things like:

• Tablet PC Input Service (in other words, all 'tablet like' PCs)
• Automated Testing tools
• Screen Readers (and other accessability software)

...will, as far as I'm concerned, break silverlight in many strange and unpredictable ways.

So now the question remains, how do we disable this automation, or otherwise get it to clean itself up?   Here are a couple resources which attempt to address the issue:

http://stackoverflow.com/questions/3306538/wpf-usercontrol-memory-leak
http://social.msdn.microsoft.com/Forums/pl/wpf/thread/d8c2c4fb-15b3-41d0-aa65-f8df4844c601

However, this approach isn't really viable as we'd have to overload every control and control template...  Ideas?

[Shaun]

Klauss,

Can you add this to your HTML / ASPX page where you declare your silverlight object, and tell me if all the problems go away?  (Be sure that your page isnt being returned from cache)

<param name="windowless" value="true" />

[Masoud]

Hi Georgi, 

could you please retry to reproduce the error Shaun and I are having with the service "Tablet PC Input Service" started?  Please note that you might need to restart the pc after enabling the service and setting its Start to automatic. Shaun, as you can see below, has done a great job of narrowing down the factors that cause this error to happen.  Please let us know if you can reproduce the error and the prospects for a solution!

Thank you for your efforts on this!

ps @Shaun I will test according to your instructions, thank you for sharing your findings!

[Ivo]

Hello,

Thank you both for your great feedback.

We successfully reproduced this at our side. It seems like an issue into the Silverlight plugin, but will need more time to investigate it and confirm it. We will write you back once we have info on this.

All the best,
Ivo
the Telerik team

[Masoud]

Hello Ivo,

thank you for your reply!

The application I am working on will be used mainly on Windows pentops.  The option of disabling the "Tablet PC Input Service" is not available to our customers.

We are currently working on rolling out the application.  I would really appreciate it if you would inform us here about the progress you are making.  If needs, we could try and postpone the roll-out for a few days.

Thank you for your help on this!

Best

[Masoud]

Hallo Ivo,

do you expect this bug to be solved in the coming two weeks?   We need to start rolling-out our application in this timeframe and our Pentop users (who constitute a majority of our users) will not be able to use the telerik RadDatePicker to choose month or year.  I would really appreciate any feedback from your side!

Thank you very much for your effort on this issue!

Best regards

[Ivo]

Hi Klaus,

We will do our best to fix this for the upcoming Q2 SP1. It will be released until the end of the month.

Kind regards,
Ivo
the Telerik team

[Steven]

Hi Shaun, 

Just wanted to thank you for your sleuthing on this issue. 

I too was affected by this bug suddenly and without cause (I thought.) 

Turns out; I have installed MultiTouchVista recently and this must have enabled the Tablet PC Input Service. 

Subsequently, when I returned to the project which uses RadDatePicker with DateSelectionMode="Month" I would get a AccessViolationException thrown when debugging and when in browser the calendar popup would break.

For now, I have disabled the Tablet PC Input Service and everything is working.

Ivo/Telerik: Any news on when this might be fixed? I'm using build 2012.2.725.1050

Thanks again, 

[Ivo]

Hi Steven,

The fix for this issue couldn't make it through for the Q2 SP1, but we will do our best to fix it for the upcoming Q3 release.

All the best,
Ivo
the Telerik team

[Masoud]

Hi Ivo,

the application we work on is used mainly by tablet-pc users.   In order for the application to function on a tablet-pc, we had to add the 

<param name="windowless" value="true" />

tag to the Silverlight markup.  This, however, makes accessing the virtual keyboard on the tablet difficult and complicates the user- experience with the application (because the "Tablet PC Input Service" is no longer available for the application).

When do you expect to release the fix?    We would really appreciate any information from you on this.

Best regards

[Ivo]

Hello Klaus,

We will do our best to fix it for the next official release of RadControls for Silverlight - Q3 2012. You can track the issue's status here.

Regards,
Ivo
the Telerik team

[Masoud]

Hello Ivo,

thank you for your reply!

Best

[G.K. Raju]

Hello Ivo,

  May i know whether the issue is fixed or not? if fixed, please provide the release details.

[Geri]

Hello G.K. Raju,

The issue is fixed with the 2013 Q3 Release. 
You can find information about the release here:

http://www.telerik.com/support/whats-new/silverlight/release-history/q3-2013

The issue in question is "AccessViolationException in RadDateTimePicker when using JAWS in Month/Year selection mode".

Hope this helps.

Regards,
Geri
Telerik by Progress