So further to my post minutes earlier, it seems Max's fix has worked. Go to Control Panel, Programs & Features, then click on view installed updates. I had 2 that were dated 11th and 10th Nov - KB5020622 and KB 5019980. I am assuming the numbers may be different because I am in Australia, so I uninstalled the KB5019980 as that number was closest to what Max posted. After restarting computer which took a few minutes, I opened up Maximizer 11 and Yipee! Everthing is working for now. It seems all other programs are working e.g. Microsoft 365, Norton, and other installed apps. I have tested most of them. So hope this helps everyone else who is having this Error 19. Thanks Max for your suggestion.