     func endAccessing() {
         if isAccessing {
             currentSource?.endAccessing()
+            localURL = nil
             isAccessing = false
         }
     }

                NSLog("[Error] \(error)")
                self.tryNextSource()
            } else {
                self.URL = source.URL
                if let completionHandler = self.completionHandler {
                    self.queue.addOperation { completionHandler(url, nil) }
                }

import Foundation

class MCResource {
    var localURL: URL?
    
    private var sources = [Source]()
    func add(source: Source) {
