Cannot get files in userDirectory with getDirectoryListing()

I'm testing getDirectoryListing() with my Android devices.

Then files are obtained using Android device (Ver.4.1.2).

but are not obtained using (Ver.6.0.1).

The code is very simple.

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var FArr:Array = File.userDirectory.getDirectoryListing();

trace("Number of files = " + FArr.length.toString() );

for(var i:int=0; i<FArr.length ; i++){

     trace("name = " + FArr.name );

}

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As written in the forum (https://forums.adobe.com/message/6748751#6748751)

I set WRITE_EXTERNAL_STORAGE permission in the app manifest.

But I've been unable to get the outputs yet.

Does anyone know the resolution?

regards