I think we need to do some maintenance on your Mac to make sure that there are no permissions errors. That can sometimes occur when updates are applied for the Operating System.
Close all your applications.
Open Disk Utility and select your Macintosh HD and then tap on the First Aid icon. The process could take a while depending on your disk size and how full it is. Grab a beer or a cup of tea and relax while it performs that task.
