Can't push App to Android Device

I have a Nexus 4 (N4) with **Android 4.2.**2 using latest version of Unity on Windows 7.

I am just doing a small test to see if I can push something to the N4. My scene is a cube with a texture on it a spotlight and the camera and that is it. No code.

I Fill out the following Player Settings: Company name Produce name Default icon Bundle identifier

I Build settings I select I select: Android (then hit Switch platform) Tick development build

I get the following error:

 Error building Player: Exception: android (invokation failed)
 ERROR: unknown error
 cmd:android list target -c
 stdout;
 stderr:
 Exception in thread "main" java.lang.NullPointerException
     at SDKMain.main(SDKMain.java:62)

I know that my PC can talk to the N4 as the app works with the Unity Remote app. And I can push non Unity apps from eclipse.

Why do I get this error?