RXjava 线程调度问题

报错
RxJava：io.reactivex.exceptions.OnErrorNotImplementedException: The exception was not handled due to missing onError handler in the subscribe() method call. Further reading: https://github.com/ReactiveX/RxJava/wiki/Error-Handling | org.litepal.exceptions.DatabaseGenerateException: can not find a class named com.test.model.Reader

disposable = Observable.create(new ObservableOnSubscribe<List>() {
@Override
public void subscribe(@NonNull ObservableEmitter<List> emitter) throws Exception {
emitter.onNext(LitePalHelper.getInstance().queryNewFriend());
emitter.onComplete();
}
}).subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Consumer<List>() {
@Override
public void accept(List newFriends) throws Exception {
if (!StringUtils.isEmpty(newFriends)) {
mList.addAll(newFriends);
mNewFriendAdapter.notifyDataSetChanged();
}else {
showViewStub();
mNewFriendView.setVisibility(View.GONE);
}
}
});