title: Data Binding: Cannot find symbol class BR
body: <p>I try to use Data Binding in my existing project, but I can't get it to build.</p>
  
  <p>Using in Project <code>build.gradle</code>:  </p>
  
  <pre><code>dependencies {
      classpath 'com.android.tools.build:gradle:1.3.1'
      //Data Binding Beta
      classpath "com.android.databinding:dataBinder:1.0-rc4"
  
      classpath 'com.neenbedankt.gradle.plugins:android-apt:1.7+'
  
      // NOTE: Do not place your application dependencies here; they belong
      // in the individual module build.gradle files
  }
  </code></pre>
  
  <p>applying</p>
  
  <pre><code>apply plugin: 'com.android.databinding'
  apply plugin: 'com.neenbedankt.android-apt'`
  </code></pre>
  
  <p>and in Module:</p>
  
  <pre><code>dependencies {
      compile fileTree(dir: 'libs', include: ['*.jar'])
  
      apt 'com.android.databinding:compiler:1.0-rc1+'
  }
  </code></pre>
  
  <p>I tried to use Data Binding with RecyclerView/Fragment/ViewHolder/Adapter..
  I use Android Studio 1.4.1.
  With compileSdkVersion 23 and buildToolsVersion "23.0.1".
  I tried it without apt, different gradle versions, proof read my classes/xml..
  I also use still Butterknife(since my project is too big to change everything at once) and other (but unrelevant) libraries.
  I synced and rebuild my project, I closed/opened Android Studio, I tried to invalidate caches. I build a 'fresh' example from start, which worked fine.</p>
  
  <p>My getter Methods in my "data class" are @Bindable.</p>
  
  <p>Also, the databinding package is not created. (error message says it doesn't exist) and <code>Error:cannot generate view binders java.lang.StringIndexOutOfBoundsException: String index out of range: -21</code></p>