HI Vince and welcome to Apple Discussions...
Try uninstalling your current copy of the Flash plugin, then reinstall new, then repair permissions.
Uninstall Flash
Install the most recent version of Flash here.
Now repair permissions.
Launch Disk Utility. (Applications/Utilities) Select MacintoshHD in the panel on the left, select the FirstAid tab. Click: Repair Disk Permissions. When it's finished from the Menu Bar, Quit Disk Utility and restart your Mac. If you see a long list of "messages" in the permissions window, it's ok. That can be ignored. As long as you see, "Permissions Repair Complete" when it's finished... you're done. Quit Disk Utility and restart your Mac.
Carolyn 🙂