title: download error: CFNetworkDownload_<some id>.tmp couldn't be moved to "" because an item with the same name already exists
body: <p>I'm using <a href="https://github.com/zlib/ObjectiveDropbox" rel="nofollow">ObjectiveDropbox</a> to manage some tasks with the user's Dropbox account, namely listing files and downloading some of them.</p>
  
  <p>Listing the files and folders from my account is pretty straigt-forward, but when I want to download a file, I get this error:
  <code>download error: CFNetworkDownload_&lt;some id&gt;.tmp couldn't be moved to &lt;unique ID&gt; because an item with the same name already exists.</code></p>
  
  <p>Any idea why?</p>
  
  <p>Code that does the download:</p>
  
  <pre><code>        DropboxDownloadArg *downloadArg = [[DropboxDownloadArg alloc] initWithPath:metadata.pathLower];
  NSURL *destURL = [NSURL fileURLWithPath:[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"]];
          [self.dropboxClient.files download:downloadArg
                         destFileUrl:destURL
                            progress:^(int64_t bytesWritten, int64_t totalBytesWritten, int64_t totalBytesExpectedToWrite) {
  
                            } success:^(DropboxFileMetadata * _Nonnull metadata) {
                                [self.downloadDelegate downloadHasCompletedSuccessfully];
                            } fail:^(DropboxError * _Nonnull error) {
                                NSLog(@"download error: %@", error.errorSummary);
                                [self.downloadDelegate downloadFailed];
                            }];
  </code></pre>
  
  <p>I checked that the downloadArg and the destURL are correctly created and valid.</p>
  
  <p>Thank you</p>