Problems with PDFView Lib

I've been having the following problem for days:

I'm using the PDFView library to load a PDF into my application.

link

Sometimes the PDF disappears, a white screen appears.

I've placed a TextView where I get and update the current PDF page.

And when I do the swiping to change the PDF page the TextView is updated even though the PDF does not appear.

I'm putting the PDF into a Fragment

I'm using the following code:

TextView txtPag;

PDFView pdfViewLe;

Integer pageNumberLe;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_le_livro, container, false);

    SharedPreferences npaginaLe = getActivity().getSharedPreferences("PAGINALE", getActivity().MODE_PRIVATE);

    txtPag=(TextView) view.findViewById(R.id.txtPag);

    pdfViewLe=(PDFView) view.findViewById(R.id.pdfview);

    if(npaginaLe.contains("pag")){
        pageNumberLe=npaginaLe.getInt("pag", 1);
    } else {
        pageNumberLe=1;
    }

    txtPag.setText(pageNumberLe.toString());
    pdfViewLe.fromAsset("le.pdf").defaultPage(pageNumberLe).showMinimap(false).enableSwipe(true).onPageChange(new OnPageChangeListener() {
       @Override
       public void onPageChanged(int i, int i2) {
            pageNumberLe = i;

            SharedPreferences npaginaLe = getActivity().getSharedPreferences("PAGINALE", getActivity().MODE_PRIVATE);
            SharedPreferences.Editor editor = npaginaLe.edit();
            editor.putInt("pag", pageNumberLe);
            editor.commit();

            txtPag.setText(pageNumberLe.toString());
       }
    }).load();

    return view;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setHasOptionsMenu(true);
}