I have Windows 7, 64bit and Internet Explorer 11 installed. I found the fix for Adobe Flash Player after 2 days of doing everything. I thought that the fix should be something very easy and it was. I spent 2 full days doing all kinds of ridiculous things, i.e. uninstalling, reinstalling, restore computer, deactiving XActive, reactivating, changing stuff under internet options, etc. The problem was Internet Explorer 11 update caused Adobe Flash Player not to work or recognize the flash player, or installing a new router caused it not to work. Websites kept displaying messages to download Adobe Flash Player when I already did. There appeared to be a conflict where some videos played and other did not. Youtube did not work anymore. All the problems that other people posted under these forums happened to me. I could not play the games I was playing before, etc. Anyway, I am NOT a tech person and understand little and almost gave up when by accident I found the fix and EVERYTHING works without rebooting anything, uninstalling or reinstalling etc. as all the people in the forums posted. Everything was so complicated!!
THE FIX: Go to Goodgle Chrome browser. If you don't have it, download it. The Adobe Flash Player is included in this browser. Anyway, at the very top RIGHT HAND SIDE there are lines in a square formation. Click on that and go to SETTINGS. Go to very bottom and click on SHOW ADVANCED SETTINGS. SCROLL DOWN TO THE VERY BOTTOM and click on RESET BROWSER SETTINGS. After I did that, EVERYTHING WORKED!!!!!!!!!!! Youtube worked, my game worked in BOTH GOOGLE CHROME AND INTERNET EXPLORER 11. It was like a miracle and a simple fix.
I hope I can save some people ALOT of aggravation and frustration. Adobe should have this fix displayed PROMINENTLY EVERYWHERE if it is indeed this simple. Let me know if this helps. All I know is that I had the same issues as everyone else in the forums and now it is all fixed. I have very limited knowledge, almost none. It just seemed that something was blocking the videos from coming up.