Could not create path to save downloaded file in cordova 3.6.3

Question

I have to store file(PDF and image) in file system wheather it is downloaded from server or taken by camera and then upload these file onto the server.

My application is only for IOS and i am using cordova 3.6.3.

on file writing time i am get the following error:

FileandFolder[44081:619630] -[CDVFileTransfer download:] [Line 365] File Transfer downloading file...
FileandFolder[44081:621465] FileTransferError {
    body = "Could not create path to save downloaded file: The operation couldn\U2019t be completed. (Cocoa error 513.)";
    code = 1;
    "http_status" = 200;
    source = "file:///Users/admin/Library/Developer/CoreSimulator/Devices/E8FAF826-8886-4EB4-BAB8-D94A48C47D64/data/Containers/Data/Application/6C8217A6-2C70-4107-96CF-9F15D412A717/tmp/cdv_photo_008.jpg";
    target = "cdvfile://localhost/root/DNI/test/10987.png";
}
FileandFolder[44081:621465] File Transfer Error: Could not create path to save downloaded file: The operation couldn’t be completed. (Cocoa error 513.)
FileandFolder[44081:619630] fileTransfer.download ==>> Some error

I followed this link Phonegap 3.0 FileTransfer download not working but still i have same issue.

I am able to access the file system and also created folder inside that but while writing the file i am getting above error.

Any help will be highly appreciated

Thank you in advance