DB Chooser failing in iOS9 - app not allowed to query for scheme

I also tried it a slightly different way:

- (void)executeDropboxImport

{

  NSLog(@">>>>> Creating chooser <<<<<");

  DBChooser *chooser = [[DBChooser defaultChooser] initWithAppKey:@"db-my_app_key"];

  NSLog(@">>>>> opening chooser <<<<<");

  [chooser openChooserForLinkType:DBChooserLinkTypeDirect fromViewController:self completion:^(NSArray *results) {

    // closure code

  }];

}

With this approach I see both of those NSLog messages, but the import fails and on the device I get the alert dialogue saying:

Unable to Generate Link

Sorry, an error occurred. Please try again later.

Nothing appears in the console (the 'not allowed to query' error doesn't appear), including the NSLog messages. In fact, I'm left in the DBChooser with no direct way to get back to my app. Of course, that may be because I'm doing it wrong. ;)