Android : Can't share internal file through bluetooth

I share a file locate in the internal memory through an intent, using the code below:

                    Uri uri = Uri.parse("content://com.mypackage/" + fileName);
                    Intent ShareIntent = new Intent();
                    ShareIntent.setAction(Intent.ACTION_SEND);
                    ShareIntent.setDataAndType(uri,"text/plain");
                    ShareIntent.putExtra(Intent.EXTRA_STREAM, uri);
                    startActivity(ShareIntent);

If I choose GMail from the list, the file is attached and sent perfectly, but if I choose Bluetooth, I receive a Toast with a "File not Sent" message. Do I have to give any special permission to the device I'm sending to?

The provider I'm using is here:

public class MyProvider extends ContentProvider {

@Override
public ParcelFileDescriptor openFile(Uri uri, String mode) throws FileNotFoundException {
    File privateFile = new File(getContext().getFilesDir(), uri.getPath());
    return ParcelFileDescriptor.open(privateFile, ParcelFileDescriptor.MODE_READ_ONLY);
}

@Override
public int delete(Uri arg0, String arg1, String[] arg2) {
    return 0;
}

@Override
public String getType(Uri arg0) {
    return null;
}

@Override
public Uri insert(Uri arg0, ContentValues arg1) {
    return null;
}

@Override
public boolean onCreate() {
    return false;
}

@Override
public Cursor query(Uri arg0, String[] arg1, String arg2, String[] arg3,
                    String arg4) {
    return null;
}
@Override
public int update(Uri arg0, ContentValues arg1, String arg2, String[] arg3) {
    return 0;
}

}

and in AndroidManifest:

        <provider android:name=".MyProvider" android:authorities="com.mypackage" android:exported="true" />

What am I missing here?