问Android makedirs文件夹创建错误

EN

public static void download(final int section){
    File folder = new File(Environment.getExternalStorageDirectory(), "/try2think"); //section"+section);
    if (!folder.exists()) {
        if(!folder.mkdirs()) {
            Log.i("Problem", "Problem creating folder");
        }
    }
    File folder1 = new File(Environment.getExternalStorageDirectory()+"/try2think", "section"+section);
    if (!folder1.exists()) {
        if(!folder1.mkdirs()) {
            Log.i("Problem", "Problem creating folder");
        }
    }
    String downloadURL = "http://jangofetthd.me/rebus/section" + section+".zip";
    final String directory = Environment.getExternalStorageDirectory()+"/try2think/section"+section+"/section"+section+".zip";
    Ion.with(Sections.context).load(downloadURL).write(new File(directory))
            .setCallback(new FutureCallback<File>() {
                @Override
                public void onCompleted(Exception e, File file) {
                    try {
                        UnzipFile(new File(directory), new File(Environment.getExternalStorageDirectory()+"/try2think/section"+section));
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            });
}