title: initctl: Unknown instance: error after Rstudio conf change
body: <p>I have a new version of R installed on an aws-machine (which always come with an old version for some reason and it's near impossible to <em>just</em> have yum or apt-get to work). I want rstudio to point to this new version which I've built from source without throwing the old version away. I therefore go to <code>/etc/rstudio/rserver.conf</code> (<a href="https://support.rstudio.com/hc/en-us/articles/200552316-Configuring-the-Server" rel="noreferrer">documentation</a>) and change the contents to: </p>
  
  <pre><code># Server Configuration File
  rsession-which-r=/root/R-3.2.1/bin/R
  </code></pre>
  
  <p>I can confirm that at this location a new version of R is installed but then I get an error after rstudio-server restarts. </p>
  
  <pre><code>root@ip-172-31-40-49 rstudio]$ rstudio-server restart
  initctl: Unknown instance:
  </code></pre>
  
  <p>What am I to do? </p>