title: Azure SQL Server Cannot Be Accessed With Active Directory Authentication
body: <p>My organization has an Azure tenant. The tenant has three subscriptions. Each subscription has multiple Azure SQL Servers. On two of the subscriptions, the databases can be accessed via one of the Active Directory authentication methods. On the third subscription, the only method of access is via SQL Server Authentication. I am the owner of this third subscription.</p>
  
  <p>If I configure an Active Directory Admin for the Server, the error I receive is:</p>
  
  <pre><code>Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'. (Microsoft SQL Server, Error: 18456)
  </code></pre>
  
  <p>When I remove the Active Directory Admin for the Server, the error I receive is:</p>
  
  <pre><code>Requested tenant identifier '00000000-0000-0000-0000-000000000000' is not valid. Tenant identifiers may not be an empty GUID.
  </code></pre>
  
  <p>How do I change this so that the SQL Servers can be accessed via Active Directory authentication? What is the best approach to determine the the differences between the subscription at issue and the other two subscriptions?</p>