RxJava2 and Kotlin : OnErrorNotImplementedException

Question

I'm using RxJava2 with Kotlin. I don't know why but I always have this error :

io.reactivex.exceptions.OnErrorNotImplementedException: An operation is not implemented: not implemented

So I add to my subscriber the onError callback, but now I have this error (inside the onError) :

kotlin.NotImplementedError: An operation is not implemented: not implemented

This is my code :

override fun getOpenBar(): Observable<List<Bar>> {

    val query: ParseQuery<ParseObject> = ParseQuery.getQuery("Bar")
    query.whereEqualTo("isOpen",true)
    return ParseObservable.find(query).toList().map { BarMapper.map(it) }.toObservable()
}

In my presenter :

override fun onAttach(view: V?) {
    super.onAttach(view)
    getView()?.printDate()
    getView()?.showProgress()
    interactor?.getBar()?.compose(schedulerProvider.ioToMainObservableScheduler())?.subscribeBy(
            onNext = {if (it.isEmpty()) getView()?.printNoResult()
            else getView()?.printBarResult(it)
                getView()?.hideProgress()},

            onError = {Log.d("TEST",it.toString())}
    )
}

How to handle correctly error ? Thanks