Androdi Studio setDownloadListener does not work on Android 6.0

Question

Even before version 6.0 the following method below works perfectly by downloading any document requested in Webview..

However now with android 6.0 in attempt to any download inside the webview the app hangs and says "The application has stopped working.".

The method below is in the same webview class.. Anyone knows how to download in android version 6?

//Método para download PDF
wv.setDownloadListener(new DownloadListener() {

    public void onDownloadStart(String url, String userAgent,
                                String contentDisposition, String mimetype,
                                long contentLength) {
        DownloadManager.Request request = new DownloadManager.Request(
                Uri.parse(url));

        request.allowScanningByMediaScanner();
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED); //Notify client once download is completed!
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "boleto.pdf");
        DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
        dm.enqueue(request);
        Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT); //This is important!
        intent.addCategory(Intent.CATEGORY_OPENABLE); //CATEGORY.OPENABLE
        intent.setType("*/*");//any application,any extension
        Toast.makeText(getApplicationContext(), "Baixando Arquivo", //To notify the Client that the file is being downloaded
                Toast.LENGTH_LONG).show();

    }
});