GetProductVersionFeatureFlag fails with Unknown Error

I have one customer where a call to GetProductVersionFeatureFlag is throwing an exception with the message “Unknown Error”. The code is not included in the exception thrown (this would be a nice addition to the LexActivatorException. Just change the last chunk of code to:

      return $"Unknown error - Code: {code}";

How do I determine what’s going wrong when I don’t have access to the error code?

Now I’m really stuck, because deactivating the license through the portal does not even fix the problem. Apparently the licenses information on the machine is corrupted somehow. How can I delete the license information from the machine so that I can reactivate the license?


If data is corrupted on the machine, you just need to reactivate the license to fix the issue.

What is the status code returned by IsLicenseGenuine function? It must have returned la_fail.

I have deleted the activation through the portal, but the application will not even startup at this point, so I can’t get any return code from IsLicenseGenuine. I believe that the call to IsLicenseGenuine is throwing an unhandled exception, but I have no proof of that.

won’t throw an unhandled exception, please check again.

I did find the cause of the problem. I am now correctly processing the IsLicenseGenuine response, and allowing the user to reactivate the license.