I "may" have a solution to the problem of Vegas not opening and thus requiring the small app (KillalVegas) to correct the issue.
I had thru the taskbar disabled the Magix "Update Notifier" in the startup section. I had done this as I was getting feed up with the ads that Magix were sending as popups.
I have since realised that I could stop these very anoying intrusions through the general preferences tab, so re-enabled the "Update Notifier".
I now no longer have any issues with Vegas opening.
Maybe others might like to try the same if they to have disabled "Update Notifier" and are having similar problems.