Activity.class - Class File Editor: The JAR file c:\sdk\platforms\android-17\android.jar has no source attachment

Activity.class - Class File Editor: The JAR file
c:\sdk\platforms\android-17\android.jar has no source attachment

For some reason a new tab opens in my debugger titled: Activity.class with
a header stating: Class File Editor and the error stating: The JAR file
c:\sdk\platforms\android-17\android.jar has no source attachment. You can
attach a source by clicking attach source below.