I've got rejected my recent update on iPhone app and it says:
"When file sharing is enabled, the entire Documents folder is used for file sharing. Files that that are not intended for user access via the file sharing feature should be stored in another part of your application's bundle. If your application does not require the file sharing feature, the UIFileSharingEnabled key in the Info.plist should not be set to true."
I don't have any data which is not supposed to backup via iTunes. So, in this case, how to make a change or appeal to pass the review?