Resolving License Validation Issues in Telerik Document Processing Libraries
Environment
| Version | Product | Author |
|---|---|---|
| 2025.2.520 | RadPdfProcessing | Desislava Yordanova |
Description
This article aims to address potential licensing issues while generating Excel (or PDF, DOCX, etc.) files with Telerik Document Processing Libraries during runtime testing. The generated file contains a "License" sheet (or a watermark) with a trial message, despite the Build Output window indicating a valid license. The issue arises in a multi-project (e.g. Blazor WASM) application setup, where dependencies are shared across projects.
Cause
This issue generally occurs due to incomplete license validation during runtime in complex setups, particularly when using shared libraries or plugin architectures. Even if the license is validated during build time, runtime environments may fail to recognize it due to transitive dependency limitations.
Solution
The Telerik.Licensing verifies the DevSeat association at the time your classlib is built, and also provisions at runtime licenses in the Root app. When you have a setup such as "Root app -> classlib -> Telerik UI", the Telerik UI will execute and verify the licensing for the classlib, but will not be applied transitively in the Root app. That's why you need to add the Telerik.Licensing NuGet package reference to Root app manually.
To ensure proper license validation and eliminate trial messages, follow the steps below:
Direct Package References: Add references to the Telerik.Licensing package directly in the Root project. This resolves transitive dependency limitations.
Explicit License Registration: Add a call to
TelerikLicensing.Register()early in your application lifecycle. For Blazor WASM applications, include this call in theProgram.csfile. This approach validates the license explicitly.Verify Assemblies: Ensure no trial versions of Telerik assemblies are referenced in any project. Replace trial assemblies with licensed ones, if such even exist.
-
Enable Diagnostics: Add the following property to your
.csprojfile to enable detailed licensing diagnostics during build and runtime:<PropertyGroup> <TelerikLicensingVerbosity>diagnostic</TelerikLicensingVerbosity> </PropertyGroup>Review the diagnostic output for clues about license validation issues.
Avoid Environment Variables: Use only the
telerik-license.txtfile for license delivery instead of environment variables, which can cause issues due to length limitations.
By following these steps, runtime validation issues should resolve, and the trial message will no longer appear in generated documents.