title: android - FloatingActionButton not showing on API 16
body: <p>I am using a <code>FloatingActionButton</code> in my Layout:</p>
  
  <pre><code>&lt;android.support.design.widget.FloatingActionButton
      android:layout_width="wrap_content"
      android:layout_height="61dp"
      android:clickable="true"
      app:fabSize="mini"
      android:src="@android:drawable/btn_star_big_off"
      android:id="@+id/floatingActionButton"
      app:layout_anchor="@+id/container"
      app:layout_anchorGravity="bottom|right"
      android:layout_gravity="start"
      android:layout_marginBottom="20dp"
      android:layout_marginEnd="20dp"
      android:layout_marginRight="20dp"
      app:backgroundTint="@color/colorAccent"
      /&gt;
  </code></pre>
  
  <p>I put an Image in it when the <code>Activity</code> is created:</p>
  
  <pre><code>favbtn = (FloatingActionButton) findViewById(R.id.floatingActionButton);
  favbtn.setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), btn_star_big_on));
  </code></pre>
  
  <p>When testing on an older Device, such as API 16, the Button is not showing/not visible. Is there a way to fix this?</p>