Cannot download a file from Dropbox to the iPad (uploads just fine) - in Swift.

I have been going around in circles trying to solve this problem. I can send files to Dropbox no problem, but cannot download them. All the delegate methods get called for sending, but the methods for downloading the files do not get called. Specifics: Core API. using Swift. iOS 8.1, using xcode. Checked and rechecked all my code. Follows is my related code:

func xferToLocal() {

    let dirPaths:[String]? = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.AllDomainsMask, true) as? [String]
    let directories:[String] = dirPaths!
    docsDir = directories[0]
    docsDirDAT = docsDir + "/" + filenameDAT
    let dropboxPath = "/" + filenameDAT
    self.restClient.loadFile(path, intoPath:docsDirDAT)
}

func restClient(client:DBRestClient, loadedFile dropboxPath:NSString, contentType:NSString, metadata:DBMetadata) {
    println("File loaded into path: \(docsDirDAT)")
}

func restClient(client:DBRestClient, loadFileFailedWithError error:NSError) {
    println("There was an error loading the file: \(error)")
}

I would appreciate any help.