Android App isn't installed

I upgraded to Unity 5 and recompiled my game and executed to my device just fine.
After editing the android manifest im stuck with this issue:

Unity generates the APK, push into device but never executes it , then i manual tap to open the game and i get this message “Android App isn’t installed”

I had a backup of the original manifest before editing so i replaced the modified with the backup , but the app still doesn’t open !!!

Any help is highly appreciated

I’m having the same issues. It was after I modified the android manifest, adding local notifications. please help