The native library gets loaded during App.start(), but you are trying to instantiate a physics control in App.main(), before App.start() has begun executing.
If you must arrange your software this way, you’ll need to explicitly load the native library in App.main() or App.setUp() like so:
Override
public void simpleInitApp() {
bulletAppState = new BulletAppState();
bulletAppState.setThreadingType(BulletAppState.ThreadingType.SEQUENTIAL);
And this is part of bulletAppState. This problem is only in compiled .jar.