Similar issue with http://wiltonprint.wilton.com/stationery/flashversion/ 

Unable to reproduce the issue on Windows 7 & windows 8.1 with Chrome stable #55.0.2883.87 , Latest canary version-57.0.2950.0 & reported version -57.0.2945.0 with the below steps:

1.launch Chrome
2.Enabled "Prefer HTML over Flash" flag
3.Navigated to below both sites.
 https://apps.facebook.com/candycrush/?fb_source=search&ref=ts&fref=ts
 https://apps.facebook.com/criminalcase/?fb_source=bookmark&ref=bookmarks&count=0&fb_bmpos=_0

4.Clicked on 'Get Adobe Flash Player'
5.Clicked on 'Allow' popup
6. Able to run the flash & game loaded successfully


Please find the attached screen cast for reference & let us know if we miss any steps to reproduce the issue.

Thanks.

Deleted: 672775.mp4 3.3 MB

	672775.mp4 3.3 MB View Download

flashplayer600@ by any chance are you seeing any shield icon in omnibox with close icon when you click on that it should say "This page is trying to load scripts from unauthenticated sources", if you click "load unsafe scripts" then should see the Flash prompt and everything should start working.

Note : Adding few people to get more insights how this should work.

Please find the attached screenshots.

Deleted: criminal_casePNG.PNG 696 KB

	criminal_casePNG.PNG 696 KB View Download

Deleted: Bug--Canary.PNG 857 KB

	Bug--Canary.PNG 857 KB View Download

Deleted: angrybirds.PNG 99 KB

	angrybirds.PNG 99 KB View Download

Adding two more URLs with Similar Issue. 
http://empire.goodgamestudios.com/
http://www.cafesonique.com/launch/getflash.html

Click on the download Flash player link on both of the above, "Allow Flash -- Run/ Block" prompt doesn't appear. 
Adding the screenshot as well. 

Deleted: Fpdownload. PNG.PNG 196 KB

	Fpdownload. PNG.PNG 196 KB View Download

Hey Raymes/ Tommy,

The interception code seems to be missing some cases, though it's not 100% clear why.  Could you take a look?

Thanks in advance.

I wonder if it's to do with iframes again. Assigning to tommycli - let me know if you need help.

raymes: No problemo, I'll take a look at this.

for empire.goodgamestudios.com, I had no problems with getting the prompt and having the game reload.

for cafesonique.com, if you browse directly just to cafesonique.com and flash isn't detected, the site _redirects_ you to /launch/getflash.html, where the navigation to get flash is correctly intercepted. Unfortunately b/c site redir'd user to /launch/getflash.html (instead of handling it on main page), chrome saves the user preference & then refreshes the getflash.html page (where the navigation was intercepted).

My own testing, with http://wiltonprint.wilton.com/stationery/flashversion/ we don't seem to be intercepting the download link (w/ prefer enabled on 56 - Beta and 57 - Canary).

in the case of apps.facebook.com, after checking the network activity when clicking on the [get adobe flash player] button, I noticed that the navigation itself was BLOCKED. apps.facebook.com is https, yet the navigation to get flash player is http. so no navigation to intercept, and no prompt since the navigation is blocked.

So far the only legit failure I see is with the wilton.com site.

After some investigation, it fails because: Google Tag Manager intercepts all link clicks in JavaScript and deconstructs the <a href="http://www.macromedia.com/go/getflash/" target="_blank">Download Flash Player</a> into two actions:

 1. Open a window
 2. Navigate the window to the http://www.macromedia.com/go/getflash/

I confirmed this by installing the Ghostery extension and blocking Google Tag Manager. Blocking that fixes the problem.

@laforge : I had no issues getting wiltonprint to work...M57.0.2943.0, intercept worked and page refreshed with Flash loaded.

ericde: That's very odd. I still have problems with wiltonprint unless I block the GTM script. I'm on tip of tree.

Unable to reproduce the issue on Windows 7,mac 10.12.2 & Ubuntu 14.04 with stable-55.0.2883.87 & latest canary-57.0.2958.3 version# as per comment#9.

Observed "Allow Flash -- Run/ Block" prompt upon clicking 'Download flash player link' button for the below URL's.

http://empire.goodgamestudios.com/
http://www.cafesonique.com/launch/getflash.html

Please find the attached screencast & let us know if we miss anything to reproduce the issue.

Thank you.

Deleted: 672775 (1).mp4 1.8 MB

	672775 (1).mp4 1.8 MB View Download

I am currently working with a similar bug with one of Google's techs and it appears that the same problem is occurring with https://apps.facebook.com/cookiejam and https://apps.facebook.com/thronerush. OS X version 10.10.5 Chrome version 55.0.2883.95 (64-bit) AND Canary Version 58.0.2991.0 canary (64-bit).

Using Ghostery to block Google Tag manager has not resolved this issue.