title: after upgrade 18.04 no gui available only tty
body: <p>After upgrading my Ubuntu desktop from 17.10 to 18.04, everything went smooth until I restarted my PC.</p>
  <p>The first suspicious thing I noticed was that it has the same grub with 17.10 - it selected the old grub from the menu (auto-select) and then showed me the boot screen. But afterwards instead of GUI I got terminal access (tty1) only.</p>
  <p>How can I fix that? I tried running:</p>
  <pre><code>sudo update-grub
  </code></pre>
  <p>but with no luck and the initial grub is still the same. How can I fix this problem?</p>