License don't expire unless you update the library to the unsupported version. Once loaded and validated, license status can not change.
What I can advise is to check the license status at startup, and throw immediately, if it is not valid:
LicenseStatus status = LicenseHelper.GetLicenseStatus();
if (status != Limilabs.Licensing.LicenseStatus.Valid)
{
throw new Exception($"License is not valid: {status}.");
}
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