Can I get older version of Telerik libraries to try to resolve an issue: Unhandled Exception: Telerik.Windows.Automation.Peers.GridViewGroupPanelAutomationPeer.GetChildrenCore()

[Joel]

This is more to any Telerik support people on the forum...

I am working on resolving an error in a Windows application that we use.  The application was originally written back in 2012 (and last updated in 2016) using Visual Studio 2010 with and C#.  Also, we are running it under Windows 10.

When debugging the source code, the underlying exception that I see is

System.NullReferenceException: Object reference not set to an instance of an object.
   at Telerik.Windows.Automation.Peers.GridViewGroupPanelAutomationPeer.GetChildrenCore()
   at System.Windows.Automation.Peers.AutomationPeer.EnsureChildren()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateChildrenInternal(Int32 invalidateLimit)
   at System.Windows.Automation.Peers.AutomationPeer.UpdateChildren()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
   at System.Windows.ContextLayoutManager.fireAutomationEvents()
   at System.Windows.ContextLayoutManager.UpdateLayout()
   at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
   at System.Windows.Media.MediaContext.InvokeOnRenderCallback.DoWork()
   at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
   at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
   at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

....

and uses an older version (2012) of the Telerik UI for WPF library (I think that is the one):

I found the following forum post

https://www.telerik.com/forums/unhandled-exception-telerik-windows-automation-peers-gridviewgrouppanelautomationpeer-getchildrencore

and wanted to try the latest version of either the 2012 (I don't know if we have those) or 2013 (depending on how much the API changed) libraries.  The issue with doing so is that (so far, still working on that) I can't find anyone here with any knowledge of an existing Telerik account or past account from which I can get the older libraries.  Would I be able to get those without having an account, at this juncture?

Thanks for any assistance in advance...

[Dilyan Traykov]

Hello Joel,

Thank you for the provided stack trace. Indeed, the exception you referenced was resolved with the 2012.3.1314 internal build as mentioned by my colleague in the forum thread. The next major version in which this fix is available is 2013.1.220.

I've gone ahead and made this version available for download from your Telerik account. Can you please check whether you're able to download it and whether using it resolves the exception at your end?

I will be awaiting your reply.

Regards,
Dilyan Traykov
Progress Telerik

[Joel]

Hello Dilyan,

We have version 2012.3.1106.40, so we are definitely behind on the 2012 releases.

When I look at my account under Downloads/Files, I can see 

Am I looking in the correct place, and, if so, which file do I need? 

Update: I downloaded the Rad_Controls_for_WPF_2013_1_0222_Trial.msi file and ran it to install, then updated the references from the 2012 files to the 2013 versions in Visual Studio and and ran a rebuild; when I run the application now, the error no longer occurs.

 

 

[Dilyan Traykov]

Hello Joel,

Indeed, you're looking at the correct page. Choosing which file to download depends on how you plan to use the Telerik assemblies.

You install the .MSI file as you have done or use the _hotfix archive. You can then update the references manually if this works for you. You can also use the NuGet package if you prefer this approach.

Please note that you can switch the License Type to Purchase if you have a developer license to avoid the Trial message shown when running your application.

Nonetheless, I'm glad to hear that the exception no longer occurs. Do let me know if I can further assist you with anything else.

[Joel]

Hello Dilyan, 

I had written a comment earlier about needing to see about buying a license; however, as it turns out, another group here has six developer licenses for DevCraft Complete.  (I finally asked the right person about it.)

However, there's still one small problem.  I can log in and see the available downloads but the versions only go back to 2015:

If you could make the earlier releases available under the account (as you did for the trial versions), that would be great.

Thanks again for all your help.

 

[Dilyan Traykov]

Hello Joel,

The Purchase versions should now also be available for download from your account. Please let me know if that is in fact true.