title: Xrandr displaying "Failed to get size of gamma for output default"
body: <p>My Sys specs : </p>
  
  <pre><code>**Intel i7-8700k (Coffe-lake),Mother board : ROG(Maximus X Hero)
  OS :Ubuntu-Gnome 16.04** 
  </code></pre>
  
  <p>I booted My new PC with <strong>Ubutnu-Gnome16.04</strong> , after installation the screen resolution is <strong>1024x768(4:3)</strong>--and screen is shown "Unknown Display".
  I havent installed anything in my new OS.My Monitor-CPU connecting Cable is <strong>DP(Pin Cable).</strong></p>
  
  <p>I have tried with "Force create new resolution": </p>
  
  <pre><code> a)cvt 1366 768 60
   b)xrandr --newmode "&lt; &gt;"
  </code></pre>
  
  <p>Then Error throws as : </p>
  
  <blockquote>
    <p>"xrandr : Failed to get size of gamma for output default".
    I want perfect resolution to be fit for my desktop screen 
    Can Anyone help me on this</p>
  </blockquote>