title: DataProtectionBuilder.ProtectKeysWithAzureKeyVault not working in .net 4.7.2
body: <p><code>ProtectKeysWithAzureKeyVault</code> is not pulling key from <code>Azure KeyVault</code> using  <code>.net 4.7.2.</code>. But it works well in <code>.netcore 2.2</code></p>
  
  <p>I do the following:</p>
  
  <pre><code>public void ConfigureAuth(IAppBuilder app)
  {
      app.UseCookieAuthentication(new CookieAuthenticationOptions
      {
          AuthenticationType = "Identity.Application", 
          CookieName = ".AspNet.SharedCookie",
          LoginPath = new PathString("/Account/Login"), 
          TicketDataFormat = new AspNetTicketDataFormat(
          new DataProtectorShim(
              DataProtectionProvider.Create(new DirectoryInfo(@"E:\SBH"), (builder) =&gt; {
                  builder
                      .ProtectKeysWithAzureKeyVault(
                          "https://test.vault.azure.net/keys/jwt",
                          "ClientID",
                          "ClientScret")
                      .PersistKeysToFileSystem(new DirectoryInfo(@"E:\SBH"));
          }).CreateProtector(
              "Microsoft.AspNetCore.Authentication.Cookies.CookieAuthenticationMiddleware",
              "Identity.Application",
              "v2"))),
          CookieManager = new ChunkingCookieManager()
      });
  }
  </code></pre>
  
  <p>The code runs without any errors / exceptions. But not making call to azure key vault.</p>
  
  <p>What is the Problem?</p>
  
  <p>I have installed these two nuget packages   </p>
  
  <ul>
  <li><p><code>Microsoft.Owin.Security.Interop</code></p></li>
  <li><p><code>Microsoft.AspNetCore.DataProtection.AzureKeyVault</code></p></li>
  </ul>