Getting error while updating telerik. web.UI DLL.

[Mukund]

We are getting below error message while updating latest telerik dll.

Severity Code Description Project File Line Suppression State
Error The project currently contains references to more than one version of System.Web.Extensions, a direct reference to version 3.5.0.0 and an indirect reference (through 'Telerik.Web.UI.RadWindowManager') to version 4.0.0.0. Change the direct reference to use version 4.0.0.0 (or higher) of System.Web.Extensions. C:\xyz.aspx

[Rumen]

Hi Mukund,

The error message you're encountering typically occurs when there's a mismatch between the versions of a dependency that your project directly references and the version that a third-party library (in this case, Telerik) indirectly references. This can happen when you update to a newer version of a library without updating its dependencies to compatible versions.

Here's how to resolve the issue:

1. Identify the Correct Versions
Ensure that the version of System.Web.Extensions you are directly referencing is compatible with the version required by the latest Telerik DLLs. In this case, Telerik seems to require version 4.0.0.0.

2. Update Your Direct Reference
You need to update your project's direct reference to System.Web.Extensions to version 4.0.0.0 to match the indirect reference required by Telerik. Here's a general approach to do this:

Using Visual Studio:

• Open the Solution Explorer: Navigate to your project within Visual Studio.
  
• Find References: Look for the References folder in your project.
  
• Remove the Old Reference: Find System.Web.Extensions version 3.5.0.0, right-click it, and select "Remove."
  
• Add the New Reference: Right-click on References, select "Add Reference," then browse to or search for System.Web.Extensions version 4.0.0.0. Select it and add it to your project.
  
• Ensure Web.Config is Updated: Sometimes, references in the web.config file also need to be updated to reflect the new version. Look for any assembly bindings for System.Web.Extensions and update the version numbers there as well.

 

Please note that as of R2 2023, Telerik UI for ASP.NET AJAX ships only assemblies compatible with .NET 4.5.x and later versions of the .NET Framework. The latest 2024 Q1 version does not support .NET 3.5 and 4.0 and you may need to upgrade the targetVersion of your project to 4.5 or higher if you want to upgrade to that Telerik release. You can find more information at: Telerik UI for ASP.NET AJAX versions compatibility with Microsoft .NET Framework.

If your project(s) run(s) on .NET 3.5 or .NET 4.0, then you have two approaches:

• [Recommended] Upgrade the .NET version of the project to 4.5+ by following the Microsoft Migrate to .NET Framework 4.8, 4.7, and 4.6.2 guide and keep the Telerik UI for ASP.NET AJAX assemblies up to date to get support for the latest browser versions, security and stability improvements as well as many new features and UI components.
• [Not Recommended] or keep the project running on .NET 3-4.0 version - you will, however, lose the opportunity to upgrade Telerik UI for ASP.NET AJAX after R1 2023 SP1 since no new builds will be produced for .NET 3.5 or 4.0 anymore.

 

Regards,
Rumen
Progress Telerik