title: iOS - Dropbox: Upload file error
body: <p>I am working on a iOS app which uploads files to Dropbox.
  First the app links user to Dropbox if he is not linked yet. Then the file is uploaded using the following DBRestClient.h method:</p>
  
  <p><code>uploadFile:(NSString *)filename toPath:(NSString *)path withParentRev:(NSString *)parentRev fromPath:(NSString *)sourcePath;</code></p>
  
  <p>All this stuff worked fine (in iOS 5 and iOS 6) but suddenly it stopped working and then when I try to upload a file I get the following error:</p>
  
  <p><strong>Error Domain=NSURLErrorDomain Code=-1021 "The operation couldn’t be completed. (NSURLErrorDomain error -1021.)" UserInfo=0xac51810 {destinationPath=(my destination path), sourcePath=(my source path)}</strong></p>
  
  <p>What can I do?</p>