title: OpenStack launching instance error
body: <p>I'm trying to launch an instance of Ubuntu in OpenStack, but I'm getting this error: </p>
  
  <blockquote>
    <p><strong>"Error: Failed to perform requested operation on instance , the instance has an error status: Please try again later [Error: Build of instance  aborted: Block Device Mapping is Invalid.]"</strong>. </p>
  </blockquote>
  
  <p>I've tried this: <a href="https://ask.openstack.org/en/question/62636/instance-creation-fails-block-device-mapping/" rel="nofollow noreferrer">https://ask.openstack.org/en/question/62636/instance-creation-fails-block-device-mapping/</a> but none of the answers seem to work in my case.</p>
  
  <p>What could I do?</p>