title: New API keys generated for v7 do not work with v5
body: <p>I have an application making use of the py-ms-cognitive wrapper (<a href="https://github.com/tristantao/py-ms-cognitive" rel="nofollow noreferrer">https://github.com/tristantao/py-ms-cognitive</a>) for Cognitive Services.</p>
  
  <p>As far as I can see in the code, it uses <code>v5.0</code> of the <code>Cognitive Services API</code>, and the API keys that I have now are for <code>v7.0</code>.</p>
  
  <p>This is the error message I receive when using a valid subscription key for <code>v7.0</code> of the API:</p>
  
  <pre><code>{ 
    "statusCode": 401, 
    "message": "Access denied due to invalid subscription key. Make sure to provide a valid key for an active subscription." 
  } 
  </code></pre>
  
  <p>I'd like to know how to navigate this issue - surely this breaks all existing production keys?</p>