title: BigQuery executing only one query
body: <p>I'm trying to run a query in the UI, but I get the error:</p>
  
  <blockquote>
    <p>Error: 6.1 - 0.0: Only one query can be executed at a time.</p>
  </blockquote>
  
  <p>I don't think there is any other queries running, and this has lasted for a while now. Surely it can handle more than one query at a time?? How long will this be stuck? How can I turn bigquery off and on again :p</p>
  
  <p><img src="https://i.stack.imgur.com/Lde6i.png" alt="enter image description here"></p>