Flash videos embedded in Facebook don't appear when played

Question

My computer is running Windows 7 Home Premium 64-bit, Internet Explorer 11, and Adobe Flash Player 14.0.0.145. I have Microsoft Security Essentials and an activated copy of Malwarebytes Anti-Malware protecting me from viruses and malware, and my IT department confirms that there is no malware infection playing a role here.
I am, however, having an odd and very frustrating problem with playing all Adobe Flash videos which are embedded inside of Facebook.com, including those which are shared from YouTube. Opening the same YouTube video in YouTube.com does not produce the same behavior - YouTube videos ALWAYS play fine on YouTube.com (whether embedded or full-screen), but NEVER play fine when they are embedded inside of a Facebook post.
NOTE: The same videos work EXACTLY AS EXPECTED in Firefox and Google Chrome, so this seems to be an IE-specific issue. This started back when I was running IE10 and has continued over into IE11.
Here is what happens in both Internet Explorer 10 and 11:
In my Facebook news feed, I locate a video I would like to watch. Before pressing Play, I see a still shot from the video with the Play icon transposed on top of the picture.
I click the Play icon to play the video in Facebook's embedded mode (where I can see other news feed messages above and below the video).
The picture disappears and turns to white (no borders, just white). Along the bottom edge of the video is a bar containing the play/pause, volume, maximize, etc. buttons. Behind these buttons I can see a faded-yet-moving view of the bottom edge of the video, but the rest of the video area is completely white.
I hear the audio playing, even though I can't see any picture other than that lower edge I just described.
If I click the maximize button at the bottom right edge of the video, the video opens to fill the screen and the video picture suddenly appears and runs as expected.
If I press ESC to get out of maximize view, the embedded Facebook screen (with the video again back to the news feed context) returns, but the picture goes white again just as in step 3, with the audio still playing as in step 4.
Right clicking on the offending video brings up a drop-down menu indicating that the video is using Adobe Flash Player 14.0.0.145.
Other videos shared in Facebook, like those from vimeo.com, play without any problem in the same Facebook.com news feed view, regardless of whether they are in embedded or in full-screen mode. Only videos using Adobe Flash Player seem affected here.
I have tried the following:
Uninstalled Adobe Flash Player. Reboot. Open Facebook.com, find the video in the news feed, which indicates that Adobe Flash must be installed. Click the link provided and install Adobe Flash from adobe.com. Return to the video in my news feed on facebook.com and click play. Same behavior as described above - no change.
Added facebook.com and youtube.com to my Trusted Sites list. No change.
Added facebook.com and youtube.com to IE's compatibility view, exited all instances of the browser, reopened. No change.
Checked for unusual browser add-ons - none found.
Cleared web cache, deleted cookies, reset browsers to default settings and default advanced settings - no change
Checked Windows Updates - all updates are current.
Ran full scans of Microsoft Security Essentials and Malwarebytes. No malware or issues found. No issues found with roguekiller, adwcleaner, and other malware-related tools either.
Any suggestions for me here? I'd really just like to click Play and see the embedded video like everybody else can. FYI, all other computers (running Vista, Windows 7, and Windows 8) on my network play these same videos in IE9, IE10, and IE11 without the problems I'm having with this one. I'd sure appreciate any help you can offer!

Answer 1

Not that the moment.  It's not ideal, but you have two working options, which is better than none. 
In all likelihood, the content providers are going to have to change code to accommodate IE11 and higher.  I spent a bunch of time this week reviewing some technical guidance that we're putting together for developers, but the long and short of it is that IE wants to developers to stop writing code that handles IE differently than other browsers. 
IE has a history of not exactly working like other browsers, and for a multitude of reasons (including how JavaScript and Flash communicate to each other), developers as a standard practice wrote a lot of code to specifically handle these quirks in IE.
To get out of this impossible position where they want markup to be the same for all browsers, but having all of this code targeted specifically at IE because of the long legacy of being problematic for web developers, IE masquerades as something else and disables features like conditional comments that allowed code to target IE.
The net result is that a lot of stuff is broken in IE11.  We're working closely with Microsoft to be good partners and help them through this transition with a few technical changes on our end, but developers are going to have to change their code and/or update the underlying libraries all over the web.  This is not going to happen overnight.  Big content providers with more resources will probably move faster than smaller sites with less developers, but it's going to be months or years before all of this shakes out.