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EasyUAClient not finding multipurpose license in UWP Xamarin app

27 Sep 2021 17:37 #10236 by support
Thank you - I am glad it works now!

Best regards

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27 Sep 2021 14:28 #10235 by sjdockendorf08

Thank you very much for the assistance. I had tried registering the license prior to accessing as well, but was getting the same error. Also apologies on the mistyped namespace, that was misconfigured when I created the test project for you.

With that said, the solution was making the license file embeded! After doing so, I now see the license get registered correctly. Understood now that .net core requires the embeded resource for a license file.
The following user(s) said Thank You: support

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25 Sep 2021 08:43 #10234 by support
I have received the project, thank you.

Upon first inspection, I can see multiple problems in your project.

1. The "Build Action" on the license key file is set to "None". It should be set to "Embedded resource".
2. Your code to register the license is commented out. You cannot expect the machine-wide license (from registry) be recognized in .NET Core projects - only the licenses in embedded resources do work.
3. Even if you uncomment the code for license registration, you must *not* try to retrieve license info *before* you register it. Doing so will give you trial license and the subsequent registration will have no effect. You need to register first and then retrieve the license info.
4. The namespace in the RegisterManagedResource call is incorrect. It should be "OPCLabLicenseTest.Licenses.Key-Permanent-ShareIt-1999523870-20201109.bin".

All of this is documented here:

Best regards

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24 Sep 2021 20:39 #10232 by sjdockendorf08

Thank you for assisting us on this. I have emailed This email address is being protected from spambots. You need JavaScript enabled to view it. with an example of the app and what we are seeing. Please let me know how else I can assist troubleshoot this issue.

Thank you!

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24 Sep 2021 13:04 #10230 by support
the licensing mechanism has not been explicitly tested under Xamarin or UWP. I cannot rule out that there is an issue; or, it might still be a mistake on your side.

I wanted to reproduce your issue, and tried to create UWP Xamarin app (which I have no experience with), but Visual Studio does not offer it to me (although I have went back to the installer and enabled the features that relate to it). tells me to create Cross-Platform > Blank App (Xamarin.Forms) but that does not match what I see in my VS.

Can you please either write a guidance on how to create a new project of the same type you are using, OR send us a (possibly shrinked-down) project that manifests the behavior? You can email to support09 (at) .

Best regards

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23 Sep 2021 17:23 #10227 by sjdockendorf08
We have a valid multipurpose license that I have installed on my machine. I have confirmed that the OPCLabs example code solutions can obtain the license serial number. This was confirmed in both .net and .net core code examples.

// Instantiate the client object.
var client = new EasyUAClient();
//Obtain the serial number from the license info.
long serialNumber = (uint)client.LicenseInfo["Multipurpose.SerialNumber"]

However, when I use these two lines of code in my UWP .net core solution, I always get the trial license serial number 1111111120. I have also tried manually registering the license using the recommended approach below, but it still isn't recognized ({namespace} was replaced with my namespace, but keeping the naming confidential here). Can you please help me with getting this working?

// The first two arguments should always be "QuickOPC" and "Multipurpose".
// The third argument determines the assembly where the license resides.
// The fourth argument is the namespace-qualified name of the managed resource.
OpcLabs.BaseLib.ComponentModel.LicensingManagement.Instance.RegisterManagedResource("QuickOPC", "Multipurpose",

We are using the nuget package library. I have tried versions 5.59.1055 and version 5.61.343

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