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Runtime Licensing Diagnostics

Updated on Jun 9, 2026

Environment

Version	Product(s)	Author
2025.3.806	Document Processing & Telerik UI	Yoan Karamanov

Description

In certain environments an application may still show a trial watermark (or trial sheet) at runtime even though everything looks correct at build time:

Valid telerik-license.txt file is present.
Build logs indicate Telerik products detected (class library and executable).
No licensing build errors are reported.

Yet the rendered UI (document, control, page) contains a watermark.

These issues surface in two categories:

Web products (ASP.NET AJAX, MVC, Core, Blazor) – Incorrect script load order or duplicate script imports where one import overrides a previously applied license.
.NET applications with extensibility or plugins (WPF, WinForms, class libraries, host wrappers) – The entry assembly at runtime differs (for example, a host like SentinelDotNetFx.dll), which changes the licensing evaluation path.

Runtime diagnostics in Telerik.Licensing help correlate what the licensing engine sees (entry assembly, loaded assemblies, product metadata, and license evidences) with the final IsLicenseValid result.

Solution

1. Enable Diagnostics Early

Call Telerik.Licensing.TelerikLicensing.EnableDiagnostics() as early as possible, before any Telerik UI controls or Document Processing code is first reached or loaded.

2. Plugin or Non-Standard Entry Scenarios

If the code runs as a plugin or a dynamically loaded context (no traditional entry assembly, or an unexpected wrapper assembly), call TelerikLicensing.Register() after enabling diagnostics to provision runtime script keys.

3. Execute

Trigger the Telerik code so the licensing pipeline executes.

4. Collect the Log

Read the accumulated diagnostics text from Telerik.Licensing.TelerikLicensing.Diagnostics and persist it (file, console). The log grows for the life of the process. Restart the process to clear it.

5. Analyze Key Sections

Look for:

Entry assembly (Assembly.GetEntryAssembly())
Product metadata extraction (ProductMetadataForAssembly ...)
License evidences (subscription or perpetual tokens)
Final resolution line (Resolved: IsLicenseValid: ...)

6. Disable When Done

Diagnostics add overhead and must not remain enabled in production indefinitely.

Performance and Operational Notes

Diagnostics add measurable overhead. Use them only during investigation.
Log size grows monotonically until you restart the process.
Capture the log after reproducing the watermark, then disable diagnostics.