Just downloaded X5 to windows 10. It gets as far as the splash page "Loading application" and then disappears. It even brought up the register page. I've tried uninstalling it and reinstalling it. I've tried the repair on the uninstall, I've tried the F8. I temporarily had the Corel 2018 trial and it seemed to work fine until it expired. Not sure what's wrong.
If you installed a CGS-2018, then removed it, be sure to remove the windows shell extension using Control Panel, then run a "repair" of X5 - it isn't removed during an uninstall.
I don't know where you bought X5 - it may be worth trying running it in compatibility mode for an earlier version of Windows.
I bought it forever ago and use it on all my computers. I just got a Surface Pro recently. How do I run it in an earlier version of Windows?