title: android - Butter Knife 8.8.1 NullPointerException
body: <p>I am using butterknife:8.8.1 like mentioned <a href="https://github.com/JakeWharton/butterknife" rel="nofollow noreferrer">here</a> </p>
  
  <p>My Project level gradle is like below</p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath 'com.jakewharton:butterknife-gradle-plugin:8.8.1'
          ...
  
      }
  }
  apply plugin: 'com.jakewharton.butterknife'
  </code></pre>
  
  <p>Module Level gradle like below</p>
  
  <pre><code>apply plugin: 'com.android.library'
  apply plugin: 'com.jakewharton.butterknife'
  dependencies {
      ...    
      compile 'com.jakewharton:butterknife:8.8.1'
      annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'
  }
  </code></pre>
  
  <p>Activity file is like below</p>
  
  <pre><code>@Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.details);
      ButterKnife.bind(this);
      ButterKnife.setDebug(true);
  }
  </code></pre>
  
  <p>xml file is like below</p>
  
  <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/device_info_layout"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:background="@color/sensor_settings_background"&gt;
  
      ....
     &lt;RelativeLayout
          android:id="@+id/container_buttons"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_alignParentBottom="true"
          android:layout_marginLeft="8dp"
          android:layout_marginRight="8dp"
          android:background="@color/settings_background"&gt;
  
          &lt;Button
              android:id="@+id/connect_button"
              android:layout_width="wrap_content"
              android:layout_height="36dp"
              android:layout_alignParentLeft="true"
              android:background="@drawable/selector"
              android:text="@string/connect"
              android:textColor="@color/red"
              android:textStyle="italic" /&gt;
  
          &lt;Button
              android:id="@+id/register_button"
              android:layout_width="wrap_content"
              android:layout_height="36dp"
              android:layout_gravity="center_horizontal"
              android:layout_marginTop="4dp"
              android:text="@string/register"
              android:visibility="gone" /&gt;
  
          &lt;Button
              android:id="@+id/unregister_button"
              android:layout_width="wrap_content"
              android:layout_height="36dp"
              android:layout_alignParentRight="true"
              android:background="@drawable/selector"
              android:text="@string/unregister"
              android:textColor="@color/red"
              android:textStyle="italic"
              android:visibility="gone"
              tools:visibility="visible" /&gt;
      &lt;/RelativeLayout&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>After compilation R2.java file is getting generated with Resource Ids
  <a href="https://i.stack.imgur.com/AuiOh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AuiOh.png" alt="R2.java res id"></a>  and   <a href="https://i.stack.imgur.com/v6rEj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/v6rEj.png" alt="resId not binding with view"></a> images.</p>
  
  <p>I am getting NullPointerException  </p>
  
  <pre><code>Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setClickable(boolean)' on a null object reference
  </code></pre>
  
  <p>Can some one help me understand what I am doing wrong here.</p>