Cannot update Norton Secure Browser

About twice a day, I get a message about, "Norton Secure Browser cannot update"  (paraphrased). I download the update executable, and run it. Every time, it starts an update, then stops after a few seconds and goes away, just vanishes. It doesn't leave any clue why it could not be updated. I always close the browser before running the update  (norton_private_browser_setup.exe) 

Is anyone else seeing this, or does anyone have a workaround?

Regards - Nigel.