Setting "AndroidJavaLibrary" from "AndroidJavaSource" on .jar file fixed my problem :-). -- View this message in context: http://mono-for-android.1047100.n5.nabble.com/Packaging-Failed-after-upgrading-to-4-0-1-tp5142301p5142369.html Sent from the Mono for Android mailing list archive at Nabble.com.