title: How to fix docker error "no subsystem for mount"?
body: <p>I pulled the <strong>drools-workbench-showcase</strong> image</p>
  
  <pre><code>docker pull jboss/drools-workbench-showcase
  </code></pre>
  
  <p>But if I try to run it in a docker container like it's proposed on the <a href="https://hub.docker.com/r/jboss/drools-workbench-showcase/" rel="nofollow noreferrer">drools-workbench-showcase</a> site:</p>
  
  <pre><code>docker run -p 8080:8080 -p 8001:8001 -d --name drools-workbench jboss/drools-workbench-showcase:latest
  </code></pre>
  
  <p>I get an error:</p>
  
  <pre><code>docker: Error response from daemon: rpc error: code = 2 desc = "oci runtime error: could not synchronise with container process: no subsystem for mount".
  </code></pre>
  
  <p>How can I fix it? (A couple of months ago I did the same and it worked without any additional efforts.) My OS is Ubuntu <strong>18.04</strong></p>