Flash Player for Windows 8 & 8.1 is embedded by Microsoft (for IE anyway) and it cannot be installed, repaired or updated from here. You can ONLY update it through Windows Update.
However, IE11 is a "rolling train wreck" thanks to Microsoft's DELIBERATE code changes that screw with User Agent ID scripts in pages and sites. The pages can't recognize the browser, so they don't recognize any of the plugins, like Flash Player. So far, Microsoft has made NO indication that they have any plan to fix it soon. In fact, they're pretty sure it's a good idea that they came up with.
Microsoft's recommendation is to use Compatibility View for affected pages, and "pretend" you're using an different browser. Trouble with that is it has seen limited success at best, and you have to individually enable it for EVERY page that has problems.
I'm not big on "pretending" so I recommend actually using another browser.
ANY of those will work where IE11 won't, with the Flash Player Plug-in (For all other browsers), and Chrome doesn't even need that because it has its own Flash Player plugin built in.