Never ending uploads with DropBox document picker export mode

Thanks Gregory for your help!

The backup is a document bundle with a custom extension '.pwbackup', so may be there is something wrong with exporting a directory like that to Dropbox, and it would be better to create a zip archive.

To do the export,  inside my app document directory I prepare a backup bundle, that contains a SQLite database, some attachments and a property list, then I present a UIDocumentMenuViewController:

let menu = UIDocumentMenuViewController(URL: backupURL, inMode: .ExportToService)

presentViewController(menu, animated: true, completion: nil)

When the user chooses the picker in the menu, I present it with:

func documentMenu(documentMenu: UIDocumentMenuViewController, didPickDocumentPicker documentPicker: UIDocumentPickerViewController) {

    documentPicker.delegate = self

    presentViewController(documentPicker, animated: true) { }

}

When the document picker is done, I get rid of the backup I prepared locally. With Dropbox, this part is never called, since the transfer doesn't succeed:

func documentPicker(controller: UIDocumentPickerViewController, didPickDocumentAtURL url: NSURL) {

    try NSFileManager().removeItemAtURL(backupURL)

} 

In my app Info.plist, I have the following exported UTIs:

<key>UTExportedTypeDeclarations</key>

<array>

<dict>

<key>UTTypeConformsTo</key>

<array>

<string>public.composite-content</string>

<string>public.database</string>

<string>com.apple.package</string>

</array>

<key>UTTypeDescription</key>

<string>Placeboard Backup</string>

<key>UTTypeIdentifier</key>

<string>com.placeboardapp.backup</string>

<key>UTTypeTagSpecification</key>

<dict>

<key>public.filename-extension</key>

<array>

<string>pwbackup</string>

</array>

</dict>

</dict>

</array>

Let me know if you need some additional info or code.