Hello Alexandre,
Did you configured your Desktop license key in the application code?
Take a look at the "Desktop Redistribution" section in the Help Documentation -> Getting Started -> Activation
using Nevron;
...
NLicense license = new NLicense("licenseKey");
NLicenseManager.Instance.SetLicense(license);
It is important to apply the license before any constructors are called.
The LockLicense property instructs the manager that no further license changes must occur.