title: Android Studio R Cannot be Resolved - Error on Clean and Gradle Build
body: <p>I am currently working on an app for my own personal use but have 1000001 problems with Android Studio - now R cannot be resolved - and cleaning gives the result below:</p>
  
  <pre><code>* What went wrong:
  Execution failed for task ':app:mergeDebugResources'.
  Error: Failed to run command:
  C:\Users\William\AppData\Local\Android\sdk\build-tools\21.1.2\aapt.exe s -i C:\Users\William\Dropbox\111 WORKSPACES 111\Android Studio\Legacy\Notifications Alarm\2015-03-24 AndroidStudioProject\app\build\intermediates\exploded-aar\com.android.support\appcompat-v7\21.0.3\res\drawable-xhdpi\abc_textfield_search_activated_mtrl_alpha.9.png -o C:\Users\William\Dropbox\111 WORKSPACES 111\Android Studio\Legacy\Notifications Alarm\2015-03-24 AndroidStudioProject\app\build\intermediates\res\debug\drawable-xhdpi-v4\abc_textfield_search_activated_mtrl_alpha.9.png
  Error Code:
      42
  Output:
  C:\Users\William\Dropbox\111 WORKSPACES 111\Android Studio\Legacy\Notifications Alarm\2015-03-24 AndroidStudioProject\app\build\intermediates\exploded-aar\com.android.support\appcompat-v7\21.0.3\res\drawable-xhdpi\abc_textfield_search_activated_mtrl_alpha.9.png ERROR: Unable to open PNG file
  
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  
  BUILD FAILED
  
  Total time: 17.777 secs
  </code></pre>
  
  <p>Above is the error message I keep on receiving when I clean my project. I can't find any XML errors, I have no foreign bodies in my resources except the launcher picture, and I can't find my R file anywhere - let alone reference it without error. The above error points to a </p>
  
  <pre><code>abc_textfield_search_activated_mtrl_alpha.9.png
  </code></pre>
  
  <p>That I have found and deleted - I don't think this is the right solution as the error persists. I have update Android Studio synched the Gradle and everything I have seen from my research. I really don't know how to handle this. </p>
  
  <p>Thank you. </p>