title: MSSQL Data collection "SQL Server activity" is empty
body: <p>I'm having an issue with the MSSQL Data colleaction "SQL Server activity" graph. It is empty and not showing any information (screenshots below):</p>
  
  <p>The graph is not visible, but the area is click-able:
  Screenshot - <a href="http://i.imgur.com/7XTV9xi.png" rel="nofollow">http://i.imgur.com/7XTV9xi.png</a></p>
  
  <p>This is showing when I click on the graph:
  Screenshot - <a href="http://i.imgur.com/DnaS2XZ.png" rel="nofollow">http://i.imgur.com/DnaS2XZ.png</a></p>
  
  <p>So far i've tried to perform the following troubleshooting steps:</p>
  
  <p>Manually collect and upload the data
  + Stop and start the collection 
  + Clear the Data collection cache files
  + Search the job history for errors - there aren't such</p>