Have always have had Licensing in Application_Start of Global.Asax file with no issues.(See below).
Since upgrading to 13.5.0.0 now receive message at the top of the document in red that aspose.words is an evaluation copy.
void Application_Start(object sender, EventArgs e)
{
Aspose.Words.License license = new Aspose.Words.License();
license.SetLicense("Aspose.Words.lic");
Aspose.Cells.GridWeb.License license1 = new Aspose.Cells.GridWeb.License();
license1.SetLicense("Aspose.Cells.lic");
}