title: How can I fix "Design editor is unavailable until a successful build" error?
body: <p>I started to learn Android Studio. I try to echo out simple &quot;Hello World&quot;:</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  &lt;RelativeLayout
      android:id=&quot;@+id/activity_main&quot;
      xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
      xmlns:tools=&quot;http://schemas.android.com/tools&quot;
      android:layout_width=&quot;match_parent&quot;
      android:layout_height=&quot;match_parent&quot;
      android:paddingLeft=&quot;16dp&quot;
      android:paddingRight=&quot;16dp&quot;
      android:paddingTop=&quot;16dp&quot;
      android:paddingBottom=&quot;16dp&quot;
      tools:context=&quot;.MainActivity&quot;&gt;
  
      &lt;TextView
          android:layout_width=&quot;wrap_content&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:text=&quot;Hello World!&quot; /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  <p>but when I clicked &quot;design&quot; view, this error is showing?</p>
  <blockquote>
  <p>Design editor is unavailable until a successful build</p>
  </blockquote>
  <p>How can I fix this error.</p>
  <p><a href="https://i.stack.imgur.com/mf1cP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mf1cP.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/5CfeX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/5CfeX.png" alt="enter image description here" /></a></p>
  <p>I just noticed that my xml code is causing error. Is that why this may be not working?</p>