Hey Scoobyroo,
Have you tried simply uninstalling and reinstalling 4.9.2 and seeing whether or not your projects load up within the Editor? If your projects are opening up within the editor, but the .exe applications created from the packaging process are not opening, could you please screenshot or copy and paste the error message when trying to run these applications? Please try to run these applications as an too.
Are you able to create a new template project, package and open the application without any trouble?
Looking forward to hearing back from you, thanks!