Runtime Exception after adding a RadComboBox?

[Rob A.]

I simply dragged the RadComboBox control from the Toolbox under "Telerik UI for WPF - Input 2020 R3" and dropped it into the designer.  This created the entry:

<telerik:RadComboBox/>

I did nothing else, build and execute project and when this Window comes to load I get a runtime error:

System.Windows.Markup.XamlParseException
  HResult=0x80131501
  Message=Could not load file or assembly 'Telerik.Windows.Controls, Version=2020.3.1020.45, Culture=neutral, PublicKeyToken=5803cfa389c90ce7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
  Source=PresentationFramework
  StackTrace:
   at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)
   at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
   at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   at TreeScapes.MainWindow.InitializeComponent() in D:\Visual Studio Projects\TreeScapes\MainWindow.xaml:line 1

Inner Exception 1:
FileLoadException: Could not load file or assembly 'Telerik.Windows.Controls, Version=2020.3.1020.45, Culture=neutral, PublicKeyToken=5803cfa389c90ce7' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

If I remove the <telerik:RadComboBox/> line, execution works.

I must admit, my success rate at using Telerik UI for WPF is pretty low, I've spent many hours researching really basic problems and hoops to jump thru to get things to "sorta" work.  I don't know what the object is with Telerik UI for WPF, but as it stands right now, it's NOT improving productivity, just the opposite.  

I'm at the point where I'll just go back to using all the default VS 2019 Microsoft controls because they just work.  My Telerik renewal is coming up in Nov and I honestly can't justify renewing.

Rob.

[Rob A.]

I resolved the issue.  It appears to be related to installing one of Telerik's older WPF Demo applications while working on my existing newer Telerik based application.  The older Telerik WPF demo was linked via Telerik online documentation.  I clicked the link to install the Demo and that installed an older Telerik.Windows.Controls.dll local to my application (see image)??

I removed the older reference and changed it to correct path/DLL version and that resolved the error.

Might want to add some word of caution on you online documentation links to older demos as they seem to cause havoc.

Rob.

[Martin Ivanov]

Hello Rob,

Thank you for sharing your feedback. Errors like the reported one usually appears if there is a mixture between the versions of the Telerik dlls, like it appeared to be the case on your side. Because of the variety of different options to setup a Telerik WPF project such issues may appear. So, if you hit this error again with the same or a different dll, please double check the referenced dlls. If you still have issues after this, I would recommend you to post the issue in the forum or contact the support via the ticketing system in your telerik.com account.

Based on your feedback we will add a KB article describing this exact issue with a resolution suggestion. Also, you can find your Telerik points updated. If you think that a different type of resource or information should be included, please tell me. 

Regards,
Martin Ivanov
Progress Telerik