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License Activation Errors and Warnings

Starting with the 2025 Q1 release, using Telerik UI for ASP.NET AJAX without a license or with an invalid license causes specific license warnings and errors. This article defines what an invalid license is, explains what is causing it, and describes the related license warnings and errors.

Invalid License

An invalid license can be caused by any of the following:

  • Using an expired subscription license—subscription licenses expire at the end of the subscription term.
  • Using a perpetual license for product versions released outside the validity period of your license.
  • Using an expired trial license.
  • A missing license for Telerik UI for ASP.NET AJAX.
  • Not installing a license key in your application.
  • Not updating the license key after renewing your Telerik UI for ASP.NET AJAX license.

License Warnings and Errors

When using Telerik UI for ASP.NET AJAX in a project with an expired or missing license, the Telerik.Licensing build task will indicate the following errors:

Error or ConditionMessage CodeSolution
No Telerik and Kendo UI License file foundTKL002Install a license key to activate the UI controls and remove the error message.
Corrupted Telerik and Kendo UI License Key contentTKL003Download a new license key and install it to activate the UI components and remove the error message.
Unable to locate licenses for all productsTKL004Your license is not valid for all Telerik and Kendo products added to your project. If you have already purchased the required license, then .
Corrupted Telerik and Kendo UI License Key contentTKL003Download a new license key and install it to activate the UI components and remove the error message.
Telerik UI for ASP.NET AJAX is not listed in your current license fileTKL101Review the purchase options for the listed products. Alternatively, remove the references to the listed packages from package.json.
Your current license has expiredTKL103, TKL104You are using a product version released outside the validity period of your perpetual license. To remove the error message, do either of the following:
- Renew your subscription and download a new license key
- Downgrade to a product version included in your perpetual license as indicated in the message.
Your subscription has expiredTKL103, TKL104Renew your subscription and download a new license key
Your trial expiredTKL105Purchase a commercial license to continue using the product.
No Telerik or Kendo UI product references detected in project.v.TKL001- If you use Telerik products and see this message, update the Telerik.Licensing package to version 1.4.9 or later.
- If you do not use Telerik products, remove the Telerik.Licensing NuGet reference from your project.

See Also