Most of the problems come from the abomination Microsoft calls a browser---Internet Exploder 11.
IE has always been the problem child of browsers, but 11 has got to be the biggest pile of garbage to come out of Redmond, WA since Vista. They rewrote the "User-Agent Strings", which websites use to identify the browswer and provide the proper content for it, like ActiveX specific things. Some sites now ID it as Gecko (Firefox) while others ID it as Webkit (Chrome or Safari). Problem is, that when the content is adjusted for those User-Agent Strings, it REQUIRES the appropriate browser engine, which IE doesn't have. EVERYTHING falls apart after that.
So far, Microsoft has made NO indication that they have any plan to fix it soon.
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.