[Solved] License requirement for windows service that hosts a blazor web site with Telerik controls

[Joel]

My project is a windows service that hosts a blazor web site and api.  When deployed using an MSI, Telerik says it is not licensed.  What must be done with the license file to ensure it is registered?

            int portNumber =
                builder.Configuration.GetValue<int>(
                    "Kestrel:Startup:Port");

            builder.Host.UseWindowsService();
            builder.WebHost.UseKestrel(options =>
            {
                options.Listen(IPAddress.Loopback, portNumber);
            });

[Dimo]

Hi Joel,

Can you please provide a small and simple test app together with instructions on how to deploy and run it? I tried creating one with the help of this article, but didn't succeed.

Another thing that you can do is obtain runtime Telerik licensing diagnostic data. This may be faster and potentially sufficient:

1. Call TelerikLicensing.EnableDiagnostics(); very early in the app life cycle, for example, in Program.cs.
2. After the UI and the Telerik license banner shows, collect and save TelerikLicensing.Diagnostics, for example, in a file.
3. Send us the file.

Thank you in advance!

using Telerik.Licensing;

// Call as early as possible, e.g. in Program.cs
TelerikLicensing.EnableDiagnostics();

// Get this later, e.g. in a Razor file
string telerikLicensingDiagnostics = TelerikLicensing.Diagnostics;

[Joel]

Okay, when you create a windows service you can double-click on it to run it in the command window.  Here is what I see from the command window that includes the diagnostics logging:

Note that I included the telerik-license.txt file as content so it resides in the same directory as the .exe

[Joel]

This is the message it displays:

 

[Joel]

I will provide a sample project if you still need that in order to solve this

[Joel]

The text from diagnostics:

Enabled diagnostics from assembly Telerik.Licensing.Runtime, Version=1.6.24.0, Culture=neutral, PublicKeyToken=98bb5b04e55c09ef
 - Location C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Licensing.Runtime.dll
 - Version 1.6.24.0
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8... reading attributes...
 - ProductCodeAttribute:
   BLAZOR
 - LicenseDateAttribute:
   2025-10-15
 - ProductNameAttribute:
   Telerik UI for Blazor
 - ProductVersion:
   11.2.0.0
 - RedistributedBy:
   Constructing Metadata...
ProductMetadataForAssembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8, Product Metadata:
 - ProductCode: BLAZOR
 - ProductName: Telerik UI for Blazor
 - ProductVersion: 11.2.0.0
 - LicenseDate: 2025-10-15
 - RedistributedBy: 
Assembly.GetEntryAssembly(): Gsi.Cloud.Upload.Service, Version=1.1.0.56, Culture=neutral, PublicKeyToken=null
Runs in a client application... Gsi.Cloud.Upload.Service, Version=1.1.0.56, Culture=neutral, PublicKeyToken=null
ElectRunTime
  ProductMetadata: ProductCode: BLAZOR, ProductName: Telerik UI for Blazor, ProductVersion: 11.2.0.0, LicenseDate: 10/15/2025 12:00:00 AM, RedistributedBy: 
  LicenseEvidences:
   - perpetual RCWPF, 2027-04-12
     eyJhbGciOiJSUzI1NiIsInR5cCI6IlRlbGVyaWsgTGljZW5zZSBFdmlkZW5jZSJ9.eyJjb2RlIjoiUkNXUEYiLCJ0eXBlIjoicGVycGV0dWFsIiwiZXhwaXJhdGlvbiI6MTgwNzUwNjAwMCwidXNlcklkIjoiMjE0MDIyMjUtMTIwYy00MzIwLWI4OGEtZGQ2NWRjNGNhOTRhIiwibGljZW5zZUlkIjoiYzlmZWU3NjEtZmM5My00OWRhLWE0NmYtNTBkZGE5ZjBjZDJkIn0.0opFSuBlnc5v9eKDN7CwkIKjN2EVs8xMI2IvRiE9mpJw8A5ZY48AHov_MOMnwIGsLcq6iHh2nvhrTrUpMjpLiKG_dl8QJ-sePjrz8soJv4CIaDTXvuLOOhL8915PVAN3tG2E5wwbMlKYYxwAIekMydY_v-ImNqcmlM7Fi7unkF5QZZr5DgpypxN37YI84Cy1gp64zjaFGssSJ0zq26S1eV4l3Jc9gNLnvGOXgwf9Dim-uc5u4wjyrmbID1IjxitqOqEtFATsusvwFWlU9h5YXRT4Iib6wXlXyvUeg_UBopJ2eyNcnKnv6biYZ3DYRuIDu22JD0Vq5SztGkfH8mGFDg
 - Resolved: IsLicenseValid: False, LicenseType: , Expiration: (null)
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...

[Joel]

The actual text from diagnostics:

Enabled diagnostics from assembly Telerik.Licensing.Runtime, Version=1.6.24.0, Culture=neutral, PublicKeyToken=98bb5b04e55c09ef
 - Location C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Licensing.Runtime.dll
 - Version 1.6.24.0
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8... reading attributes...
 - ProductCodeAttribute:
   BLAZOR
 - LicenseDateAttribute:
   2025-10-15
 - ProductNameAttribute:
   Telerik UI for Blazor
 - ProductVersion:
   11.2.0.0
 - RedistributedBy:
   Constructing Metadata...
ProductMetadataForAssembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8, Product Metadata:
 - ProductCode: BLAZOR
 - ProductName: Telerik UI for Blazor
 - ProductVersion: 11.2.0.0
 - LicenseDate: 2025-10-15
 - RedistributedBy: 
Assembly.GetEntryAssembly(): Gsi.Cloud.Upload.Service, Version=1.1.0.56, Culture=neutral, PublicKeyToken=null
Runs in a client application... Gsi.Cloud.Upload.Service, Version=1.1.0.56, Culture=neutral, PublicKeyToken=null
ElectRunTime
  ProductMetadata: ProductCode: BLAZOR, ProductName: Telerik UI for Blazor, ProductVersion: 11.2.0.0, LicenseDate: 10/15/2025 12:00:00 AM, RedistributedBy: 
  LicenseEvidences:
   - perpetual RCWPF, 2027-04-12
     eyJhbGciOiJSUzI1NiIsInR5cCI6IlRlbGVyaWsgTGljZW5zZSBFdmlkZW5jZSJ9.eyJjb2RlIjoiUkNXUEYiLCJ0eXBlIjoicGVycGV0dWFsIiwiZXhwaXJhdGlvbiI6MTgwNzUwNjAwMCwidXNlcklkIjoiMjE0MDIyMjUtMTIwYy00MzIwLWI4OGEtZGQ2NWRjNGNhOTRhIiwibGljZW5zZUlkIjoiYzlmZWU3NjEtZmM5My00OWRhLWE0NmYtNTBkZGE5ZjBjZDJkIn0.0opFSuBlnc5v9eKDN7CwkIKjN2EVs8xMI2IvRiE9mpJw8A5ZY48AHov_MOMnwIGsLcq6iHh2nvhrTrUpMjpLiKG_dl8QJ-sePjrz8soJv4CIaDTXvuLOOhL8915PVAN3tG2E5wwbMlKYYxwAIekMydY_v-ImNqcmlM7Fi7unkF5QZZr5DgpypxN37YI84Cy1gp64zjaFGssSJ0zq26S1eV4l3Jc9gNLnvGOXgwf9Dim-uc5u4wjyrmbID1IjxitqOqEtFATsusvwFWlU9h5YXRT4Iib6wXlXyvUeg_UBopJ2eyNcnKnv6biYZ3DYRuIDu22JD0Vq5SztGkfH8mGFDg
 - Resolved: IsLicenseValid: False, LicenseType: , Expiration: (null)
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...
License<T>() type assembly Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8
License(Telerik.Blazor, Version=11.2.0.0, Culture=neutral, PublicKeyToken=20b4b0547069c4f8)
 - Location: (C:\Program Files (x86)\Grason-Stadler\GSI Cloud Upload Service\Telerik.Blazor.dll)
 - Version: (11.2.0.0)
ProductMetadataForAssembly cached
Quick return from cache...

[Dimo]

Hi Joel,

Thanks for the update. The log shows that our runtime license validation finds a license only for WPF, but not Blazor:

  ProductMetadata: ProductCode: BLAZOR, ProductName: Telerik UI for Blazor, ProductVersion: 11.2.0.0, LicenseDate: 10/15/2025 12:00:00 AM, RedistributedBy: 
  LicenseEvidences:
   - perpetual RCWPF, 2027-04-12

The problem may be similar to the scenario in which Telerik UI for Blazor is used by a dependency project or a Razor Class Library:

https://www.telerik.com/blazor-ui/documentation/installation/license-key#using-telerik-packages-in-referenced-projects

My suggestion is to reference the Telerik UI for Blazor NuGet package directly in your main startup project, even if it's the desktop part of the app. If this does not help, then please send us a small isolated solution, which reveals your project structure, so that we can run and test it locally. Thanks.