After update Android SDK revision 21 for building application with Android 4.2. But now, I can’t set Android Project Build target anymore.
Steps in procedure:
-
Updated Android SDK platform and platform tools to revision 21 via Android SDK manager.
-
Updated ADT plugin for eclipse to revision 21.
-
Restart Eclipse.
This is Android entry in Eclipse Preferences.

This is my project’s properties:

Thanks in advanced.
At least, I have to install the latest Eclipse IDE to make it works.
My old eclipse version:
and the latest: