That may or may not mean a lot, I'm sure, but it's the root of your problems, and Flash Player has nothing to do with it.
Microsoft "rewrote" the User-Agent Strings for the abomination they call their latest and greatest browser. User-Agent Strings are what websites use to identify the browser you're using and provide the proper content for it's browser engine, like ActiveX stuff, and Flash or HTML5 video. Thanks to the geniuses in Redmond, WA, the User-Agent Strings for IE11 (which has a Trident engine), ID it as either "Gecko" (Firefox) or "Webkit" (Chrome). Problem is: when the site the directs to the content for one of these two engines, the Trident engine in IE can't intepret it and the site then sees IE as an "unidentified" browser.
The problem with an unidentified browser is that the plug-ins in that browser aren't recognized either, so even though you're up to date, it says you need the latest Flash Player when you use IE11. YouTube... has converted to HTML5 video so if it doesn't detect Flash Player, it can display HTML5 (MP4) video which requires no plug-in to play. Facebook can't do that, because HTML5 doesn't apply to games... only video.
Microsoft has no plans to "fix" the mess thay've created because they think it's a great idea to block you out of the websites you visit.
They recommend using "Compatibility View" and pretending that you're using an older verison of IE... Problem with that is that it's seen limited success, and you have to enable it for EVERY page that has problems... individually.
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.
Thanks much for the explanation, still trying to digest the time line that would create this situation. Looks like 184.108.40.206 was released early February, I had assumed it was a brand new release given the demand now for a Flash update, which you’ve explained is apparently a false report by IE. But I am not seeing any updates to Windows or IE on that machine since February either, so not sure how changes in the user-agent strings (you’re right, never heard of them before) would have been implemented. Also odd that my other computers have the same configuration and they run fine. Probably more than I want to know, anyway, but it seems there must be a setting that differs. Will get use to Chrome.
I am certainly not a fan of Redmond, though chained to their products for good and ill (BTW, this seems like an Onion satire but apparently not?:
http://www.newyorker.com/online/blogs/borowitzreport/2014/02/gates-spends-entire-first-day -back-in-office-trying-to-install-windows-81.html) If not for his philanthropy, I'd hope that this was Bill's Groundhog Day. Does seem odd, even for MS, to know of a problem of this magnitude and not fix it. Maybe they are getting ready to release their own flash player....
With Windows 8, the UAS problem was apparent from October 18, the day that 8.1 and IE11 were released. With 7, it didn't and doesn't happen right away. There's really no rhyme or reason to it. One day it works and the next it doesn't. I don't know if there are Windows cache files that "dump" on a reboot and then enable the new UAS, or what it is, but for the first month and a half, I hardly saw anything out of IE11 and Win 7. Now it seems there at least two a day that I get. Makes me glad I'm on a Mac, and Windows is only virtual machines for me anymore. I still have IE for testing in XP, Vista, 7, 8 & 8.1, but my Mac Mini is my workhorse and it "works". That's why I switched 12 years ago.
I am in the same situation. No flash player for my IE 11 with Windows 7 Ultimate. I try everything with the exception of re-installing Windows itself. Had to use another computer to watch video. Exremely frustrated at Adobe for this. Nothing works on my primary computer for video viewing. My back up computer wanted to upgrade I caught it just in time. It works with IE9 and I can do my thing but what am I going to do with my new desktop?
I read the previous comments and then I uninstalled IE11 and it defaulted to IE10 and then made change to "Tools, Compatibility View" and now Flash Player works again! All it took was like 4 hours to get to here! This is total madness what is happening here! I hate to think what it is like for a nontech, non computer person would be doing faced with this situation! LOL!
Another Solution....Based on Mike M's comment about IE settings and cache, i went to IE11 advanced settings and reset to default, including compete clean-up of all cookies, etc. after restoring IE11 settings flash worked immediately without having to even reinstall. So didn't have to go back to 10, and that was a great solution i nerver would have come up with, so thanks Mike! (We'll see if it lasts)
BTW, i am an apple fan and tried to convert in 2009. Had to have a virtual windows to run WordPerfect, as I despise Office even more than Windows, used Parallel, and after a different problem every day for three months avoided further intense suicidal depression via the irony of returning to MS...