First time here?

You are looking at the most recent posts. You may also want to check out older archives. Please leave a comment, ask a question and consider subscribing to the latest posts via RSS or email. Thank you for visiting!

Today we released an update to Silverlight 4 (update build is 4.0.50826.0) along with an updated SDK.  We appreciate our customers’ patience on working with us to help identify and verify necessary updates to this service release.  You can find all the details in KB2164913.  Here are the relevant highlights:

  • SDK feature to enable Add New Row capabilities in DataGrid control
  • Improving startup performance of Silverlight applications
  • Adding mouse wheel support for out-of-browser applications on the Mac platform
  • Various media-related fixes around DRM content
  • Fixed memory leak when MouseCapture is used
  • Fixed memory leak for DataTemplate usage

All the installer links have been updated to leverage these new bits for our customers.

For end users

For end users, having them simply install the runtime will provide them with the updated bits and benefits of the fixes/features in this service release.  The best way to force encourage your users to upgrade to this service release would be to leverage the MinRuntimeVersion attribute of your object tag:

   1: <object data="data:application/x-silverlight-2," type="application/x-silverlight-2"
   2:     width="640" height="400">
   3:     <param name="source" value="YOUR_PATH_TO_XAP" />
   4:     <param name="background" value="white" />
   5:     <param name="minRuntimeVersion" value="4.0.50826.0" />
   6:     <param name="autoUpgrade" value="true" />
   7:     <a href="http://go.microsoft.com/fwlink/?LinkID=149156&amp;v=4.0.50826.0" style="text-decoration: none">
   8:         <img src="http://go.microsoft.com/fwlink/?LinkId=161376" alt="Get Microsoft Silverlight"
   9:             style="border-style: none" />
  10:     </a>
  11: </object>

Notice lines 5 and 6 above.  This would trigger that the end user is required for your application to run and require them to upgrade. The minRuntimeVersion/autoUpgrade are the minimum to require your user to upgrade to the later version.  Ideally you would follow good installation experience guidance (see “Installation Experience Whitepaper” with complete sample source code) to customize your install and/or upgrade experience.

For Developers

If you are a developer and authoring Silverlight applications you may want to grab the new developer bits and updated SDK:

I would install the developer build first and then the SDK and you’ll have a refreshed environment.  As with any release we try to get you the information as soon as possible and sometimes the information flows faster than the download servers replicate.  If you aren’t getting the updated bits using the links above, please be patient as the download servers from Microsoft refresh their replication caches. 

Note that when you now create a new project you’ll be using the new SDK and so the minRuntimeVersion (see above) of the project templates as well as compiled bits for your SL4 application will be using/requiring the updated runtime.

There are NO Visual Studio tools updates for this release so the Silverlight4_Tools.exe package is not needed to re-install.

For Visual Studio LightSwitch Users

When Visual Studio LightSwitch shipped they included a pre-release later build of Silverlight 4.  This caused some issues for customers who were using a single machine to evaluate LightSwitch but also using the same machine.  Any Silverlight 4 application developed and deployed would give customers messages indicating that they needed a later version of Silverlight, but were unable to acquire a compatible version!

This is now solved with this service release.  Simply put: If you are using LightSwitch, install the updated developer runtime and SDK.  This will solve this issue and allow you to develop LightSwitch applications as well as production Silverlight 4 applications.

Hope this helps!  As always if you have feedback on Silverlight, here are some methods of providing feedback to our team.

This work is licensed under a Creative Commons Attribution By license.

9/1/2010 1:23 PM | # re: Silverlight 4 service release (September 2010)
Can you provide a little more detail about what Add New Row capabilities means?
9/1/2010 1:42 PM | # re: Silverlight 4 service release (September 2010)
Thanks for this. I'd love to see some perf improvements on the Mac plugin though :)
9/1/2010 2:08 PM | # re: Silverlight 4 service release (September 2010)
kb link still doesn't work for me.
9/1/2010 3:18 PM | # re: Silverlight 4 service release (September 2010)

Was hoping this release would allow one to set the default file name for a SaveFileDialog.

Check this post out, many users have reported this. How can we get Microsoft to help?


9/1/2010 3:45 PM | # re: Silverlight 4 service release (September 2010)
KB link is still not working. Any word on that? We'd really like to know which of our vendor-release-dependent bugs have now been addressed.
9/1/2010 6:15 PM | # re: Silverlight 4 service release (September 2010)
Thank you Tim. Am I right in saying that if I already have the Silverlight 4 Tools for VS installed, I need to install both the Developer Runtime as well as the SDK to get the latest?
9/2/2010 2:50 AM | # re: Silverlight 4 service release (September 2010)
I have installed this sdk and I have a error connection it.
I have a SL4 project and there is a DataGrid.
The ItemSource of DataGrid is a PagedCollectionView.

I get the following error message:

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 1.1.4322; InfoPath.2; .NET4.0C; .NET4.0E; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)
Timestamp: Thu, 2 Sep 2010 06:43:28 UTC

Message: Unhandled Error in Silverlight Application
Code: 4004
Category: ManagedRuntimeError
Message: System.ArgumentOutOfRangeException: Index must be within the bounds of the List.
Paraméter neve: index
Hely: System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
Hely: System.Collections.Generic.List`1.Insert(Int32 index, T item)
Hely: System.Windows.Controls.DataGridDisplayData.LoadScrollingSlot(Int32 slot, UIElement element, Boolean updateSlotInformation)
Hely: System.Windows.Controls.DataGrid.InsertDisplayedElement(Int32 slot, UIElement element, Boolean wasNewlyAdded, Boolean updateSlotInformation)
Hely: System.Windows.Controls.DataGrid.InsertDisplayedElement(Int32 slot, Boolean updateSlotInformation)
Hely: System.Windows.Controls.DataGrid.GetExactSlotElementHeight(Int32 slot)
Hely: System.Windows.Controls.DataGrid.UpdateDisplayedRows(Int32 newFirstDisplayedSlot, Double displayHeight)
Hely: System.Windows.Controls.DataGrid.ComputeScrollBarsLayout()
Hely: System.Windows.Controls.DataGrid.MeasureOverride(Size availableSize)
Hely: System.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)

Line: 59
Char: 4
Code: 0
URI: http://localhost:6000/Default.aspx

Please somebody help me!
9/2/2010 4:30 AM | # re: Silverlight 4 service release (September 2010)
The problem occours when I add a GroupDescription to the PagedCollectionView.
9/2/2010 5:38 AM | # re: Silverlight 4 service release (September 2010)
I don't think is binding problem, because I just get this error after I upgraded sl sdk.

I find out when datagrid is loaded, and after that I add GroupDescription to CollectionView the problem doesn't occour.

Where can I send my app?
9/2/2010 1:18 PM | # re: Silverlight 4 service release (September 2010)
"Jer - I know it is on the backlog of items."

Any chance of getting it bumped up in the queue? From what I can tell it's a rather quick fix which many people are anxiously awaiting.
9/2/2010 4:33 PM | # re: Silverlight 4 service release (September 2010)
Tim and co- where can I find out more information regarding the changes in the expression media player as described in the kb article?
9/2/2010 9:49 PM | # re: Silverlight 4 service release (September 2010)
Tim, Thanks for your response. Any chance in merging those 2 feature suggestions. The one you provided and this one?


That would get the total votes for this past 300 (241 + 91).

9/3/2010 7:02 AM | # re: Silverlight 4 service release (September 2010)
Awesome news, too bad the Firefox MessageBox crash hasn't been fixed though... Really hoping GDR1 would take care of that.

9/3/2010 7:18 AM | # re: Silverlight 4 service release (September 2010)
You mention that you can increase Isolated Storage size via the registry - what about on Macs? Any .plist modifications to increase storage space or some such?
9/3/2010 8:29 AM | # re: Silverlight 4 service release (September 2010)
Has this patch been included in the non-developer silverlight client? What I'm wondering is do I need to install the updated sdk and rebuild all my xap files to take advantage of these fixes or do I just need to set the updated minimum runtime version on my host page?
9/3/2010 9:00 AM | # re: Silverlight 4 service release (September 2010)
Any chance this fix had also fixed the sound stutter problems with MediaElement?
For some reason sound effects that didn't play well because of the infamous Silverlight stutter sound problem, suddenly work flawlessly.
9/3/2010 9:50 AM | # re: Silverlight 4 service release (September 2010)
I noticed sometthing on the Microsoft download site related to these updates:

Microsoft Silverlight 4 Tools for Visual Studio 2010 now have a date of 9/2/2010.
The version of these says 30319.352 yet in my Programs area of the control panel it says 10.0.30319.400 (note I have recently installed the two updates mentioned in this post).

Does this mean the new post contains the September developer runtime and sdk updates or not? My question is if we are building up a new developer system and apply these tools dated 9/2 do we still have to apply the other updates separately? Given the newer date but also the differences in the version numbers I am unsure. If the current tools download still should have the September SDK and Developer runtime updates applied Microsoft should edit the tools download page to say so.
9/3/2010 10:00 AM | # re: Silverlight 4 service release (September 2010)
I encounter the same problem joesimon has, only using CollectionViewSource with group descriptors. Any news about the error?
9/3/2010 2:27 PM | # re: Silverlight 4 service release (September 2010)
We have a native os x launcher application that runs on startup and that could modify the .plist, so lack of group policy isn't a deterrent.

Our product is aimed at special education, and the dialog that pops up asking for more space (while great for 99% of the population) isn't user friendly enough for our target audience.

Additionally a large portion of our audience is only able to utilize our software because it's designed such that most things can be done with only one key press (software switching) to help those with motor disabilities - they don't have the coordination to click "yes" on the pop-up so we have to have a "pre-dialog" telling them to ask their teacher for help.
9/3/2010 3:52 PM | # re: Silverlight 4 service release (September 2010)
Regarding my comment about Expression Encoder...

Thanks, thats what I meant to ask about but I was mid conversation with someone and what I typed came out wrong. We are dealing with some unique media element sync requirements that aren't natively handled, so the MediaStreamSource implementation update is pretty exciting for us. Today we dug around a bit and what I think we see is a game changer for us. It looks like our "No we can't do that in silverlight" has become a "maybe with a high probability of yes."

Keep up the good work and thanks for keeping the community in the loop!
9/4/2010 6:52 AM | # re: Silverlight 4 service release (September 2010)
Tim - I sent to you my project 2 times.
(I sent 3 mail for you and last 2 has attachment)
Didn't get you? I will send to you again.
9/5/2010 8:58 AM | # re: Silverlight 4 service release (September 2010)
I am not able to reproduce the problem in a simple project, but found out that the real problem occurs before the actual exception. The problem starts with the datagrid not showing records while they are present in the ItemsSource. Now when the grid is resized or animated, the exception will be thrown.

Hope this helps.
9/5/2010 11:37 PM | # re: Silverlight 4 service release (September 2010)
I'm interested about the status on the bugfix of the issue related by JDCebrian
Can we hope a solution (or a little explanation about how to pass through this issue) for this year ?!

By the way thanks, i'm really happy about the inline data template memory leak fix ! :D
9/6/2010 3:42 AM | # re: Silverlight 4 service release (September 2010)
When will this be released for Chrome on Mac OS X?
9/6/2010 10:38 AM | # re: Silverlight 4 service release (September 2010)
I found the problem. The combination of IsReadonly="True" and asynchronous itemssource will cause the crash.
I sent you a project which will reproduce the problem.
9/7/2010 1:24 AM | # re: Silverlight 4 service release (September 2010)
Rick - Thank you very much!!!
It works. This was the problem.
The new DataGrid control is wrong.
I temporary swiched off the IsReadOnly property.
9/7/2010 4:53 AM | # re: Silverlight 4 service release (September 2010)
Are you sure that the DataTemplate issue is fixed in this release? I'm still seeing memory leaks in my application. I ran windbg and it shows that my User Controls are locked by DataTemplate.

9/7/2010 5:25 AM | # re: Silverlight 4 service release (September 2010)

Visual Studio won't have to be closed as there are no updates. Half way through the install, I get prompted with a conflict with Visual Studio 2010. Ignoring didn't work out so well.

Now I can't even kill the VS 2010 process that is showing as open even though i closed all instances of VS 2010 just to be on the safe side.

9/11/2010 10:14 AM | # re: Silverlight 4 service release (September 2010)
How come we don't have the possibility to set the Filename in SaveFileDialog yet?
How many people stating this does Microsoft need to see before it includes this feature into Silverlight?
9/13/2010 7:03 AM | # re: Silverlight 4 service release (September 2010)
Hi Tim
How does the Datagrid Add New Row functionality appear (I notice you use the word "enable" so perhaps there's some work to do?) I can't see any method on Datagrid to do it. I have re-made all project refs and updated minruntime version.

Anthony White
9/13/2010 10:01 AM | # re: Silverlight 4 service release (September 2010)
9/21/2010 1:04 PM | # re: Silverlight 4 service release (September 2010)

We updated to the latest version, getting this error and a blank page randomly.. any thoughts?? Thanks!!

at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
at MS.Internal.XcpImports.FrameworkElement_MeasureOverride(FrameworkElement element, Size availableSize)
at System.Windows.FrameworkElement.MeasureOverride(Size availableSize)
at System.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)
9/30/2010 12:36 AM | # re: Silverlight 4 service release (September 2010)
Hi Tim,

Has there been anything documented about implementing ICollectionView to get add row functionality on the data grid?


9/30/2010 1:24 PM | # re: Silverlight 4 service release (September 2010)
I am working on a public facing Silverlight 4 application for the state of Wisconsin. I recently observed a rather huge memory leak in my application. I found this blog post of yours during my search for a possible solution. I downloaded and installed the updates mentioned in this post. I am using listbox controls with templates as static resources as suggested. I can still observe the memory leaks in Task Manager when ever I simply scroll the items in any listbox control in my application, regardless of how it is configured. I will be taking this application public in a couple of months, and I need to find out why this occurs and get it fixed. Based on a long couple of days of researh, this appears to have been a problem in Silverlight 4 for a long time. Does Microsoft ever plan to fix it?
10/11/2010 1:48 PM | # re: Silverlight 4 service release (September 2010)
Hi Tim,

I am currently using the latest version SL4 (4.0.50917.0) and still facing the memory leak issues of Datagrid or any control that uses Ver/Hor scrollbars. I used PagedCollectionView of POCO objects as its ItemSource. I have spent a lot times trying to figure out why...Please help...deadline is coming.

Thanks a lot in advance.
12/16/2010 9:11 AM | # re: Silverlight 4 service release (September 2010)
Hi Tim,

Does the runtime 4.0.50917.0 include the fixes of the 4.0.50826.0 version?

12/20/2010 5:24 AM | # re: Silverlight 4 service release (September 2010)
Happy to see your blog as it is just what I’ve looking for and excited to read all the posts. I am looking forward to another great article from you.
I am developing a "dashboard" application using Silver light and Prism together. It is really amazing what I've accomplished so far but I continue to have memory usage issues.70-089 70-235 70-237 I saw that this update helped with some memory leaks so I installed it. It still does not stop the application from continuing to hold onto memory. Will there be more updates to address memory leak issues or is there any advice
8/18/2011 9:20 PM | # re: Silverlight 4 service release (September 2010)
Well, your blog is really useful for many people I think. You helped me in various situations because I many times I have found the useful information which was really important for me in your site. Reading this your post I have known many new things about the various smart-phones models which I have not known before. It is really great that you share for us such useful stuff. Thanks a lot one more time for the useful information. Thanks for publishing these articles here, your blog will be better than any book for me bankruptcy attorney vancouver wa
9/23/2011 10:51 AM | # re: Silverlight 4 service release (September 2010)
Wow!! What a great topic, really I appreciate such kind of topics. It will be very helpful for us. Waiting for more articles, blogs like this. I’m going bookmark your blog for future reference. Thanks a lot for sharing this side effects of steroids
9/27/2011 10:35 PM | # re: Silverlight 4 service release (September 2010)
Hello,I love reading through your blog, I wanted to leave a little comment to support you and wish you a good continuation. Wishing you the best of luck for all your blogging efforts. Thanks for posting this useful article wireless alarms
11/12/2011 7:56 PM | # re: Silverlight 4 service release (September 2010)
5: <param name="minRuntimeVersion" value="4.0.50826.0" />
6: <param name="autoUpgrade" value="true" />

What does the value indicate in line 5?
12/14/2011 7:51 AM | # re: Silverlight 4 service release (September 2010)
I found this after working on a PagedCollectionView - ArgumentOutOfRangeException: Index must be within the bounds of the List.
for ages! Very helpful...


This won't work :


This fix, thanks a lot Telos, will work :

while (DataGrid.Columns.Count != 0)


The exception is raised from the "Add" or "Insert" methods;

so it seems like the "Clear" method leaves the Columns (or anything else on which it depends) in a bad state.

Does a bug report exist for this bug ?

Please add 4 and 1 and type the answer here:


The opinions/content expressed on this blog are provided "ASIS" with no warranties and are my own personal opinions/content (unless otherwise noted) and do not represent my employer's view in any way.