title: Fail using Azure ServiceBus Topic from Framework 4.5.1
body: <p>my client is WebForm running on framework 4.5.1 (using Microsoft.ServiceBus 1_1, and my server is .netcore running on azure.</p>
  
  <p>the servicebus is running on azure.</p>
  
  <p>my problem started when the client is running, trying to connect to a subscriber but get an exception cause the subscriber does not exists yet(which is a valid scenario causer the server might not send a notification yet).</p>
  
  <p>so, i try to check if there is a subscriber and create it if not exists.
  when I try to create the subscription from the client it gives me an error:
  The incoming request is not recognized as a namespace policy put request.</p>
  
  <p>creating a subscription from the server works.</p>
  
  <p>Client code:</p>
  
  <pre><code>var name = NamespaceManager.CreateFromConnectionString(serviceBusConnectionString);
  
          if (!name.SubscriptionExists(topicName, subscription))
          {
              SubscriptionDescription sd = new SubscriptionDescription(topicName, subscription);
              RuleDescription rd = new RuleDescription("filter1", new SqlFilter($"sys.To={subscription_managerId}"));
              name.CreateSubscription(sd, rd); // fail here
          }
          _subscriptionClient = SubscriptionClient.CreateFromConnectionString(serviceBusConnectionString, topicName, subscription, ReceiveMode.ReceiveAndDelete);
  </code></pre>
  
  <p>any idea?
  thanks for all the helpers</p>