Runtime Licensing Diagnostics

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 looked 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 mainly 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 / plugins (WPF, WinForms, class libraries, host wrappers) - The entry assembly at runtime differs (e.g. a host like SentinelDotNetFx.dll), changing the licensing evaluation path.

Runtime diagnostics in Telerik.Licensing help correlate what the licensing engine sees (entry assembly, loaded assemblies, product metadata, 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/loaded.

2. Plugin / 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 to clear).

5. Analyze Key Sections

Look for:

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

6. Disable When Done

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

Performance & Operational Notes

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