Enabling Flash Player after 12th January 2021

To enable flash you need to configure the flash player via a config file.

So Adobe put a killswitch in many flash player upgrades ago, and never told anyone publicly… well until about December last year…..

The joy of living in New Zealand is that we are the first to see the new day. Downside is that anything that is time-bombed, we get to see first as well…..

So come the 12 January 2021, the morning brings us helpdesk calls of flash has stopped working. Tidings of great joy.

Not only that , but Adobe has stopped you from downloading flash from their site

It also appears that any new install of a browser will not be able to download a flash plugin relevant for the browser

The solution is to whitelist the URLs you need in a flash config file

Details are here under Chapter 4 – Enterprise Enablement

Adobe Flash Player Administration Guide for Flash Player | Adobe Developer Connection

Short answer for IE11

Is to put a mms.cfg file into the following locations



This covers both the 32 and 64 bit version of IE11

Example MMS.CFG file

AllowListUrlPattern= http://www.ultrasounds.com/
AllowListUrlPattern= https://www.ultrasounds.com/

Restart IE11

The website in the example file is one referenced in Google Chrome documentation, Preparing your enterprise for Flash deprecation | Google Cloud Blog so I am happy to use it as a reference test site.

Short answer for Google Chrome

Read the document Adobe Flash Player Administration Guide for Flash Player | Adobe Developer Connection, page 36.

I quickly tried Google Chrome, but could not get it to work. That’s my job for tomorrow, but in reality Chrome V88 and higher will just break things anyhow, so I am only going to spend time on this if we really need something running in Chrome that cannot run in IE11

Short answer for MS Edge

You should be able to follow the Chrome instructions

Directory appears to be

C:\Users\<username>\AppData\Local\Microsoft\Edge\User Data\Default\Pepper Data\Shockwave Flash\System and is user based like Chrome

MS Edge V88 and higher will remove support to a point as it is based on Chromium , but MS Edge V88 is able to rely on the IE11 engine to use flash.

I am sure that there will be some location to put the mms.cfg file in, but MS Premier Support have been less than helpful in this whole event, stating that you cannot enable flash again after 12/01/2021

Update on Adobe Flash Player End of Support – Microsoft Edge Blog (windows.com)

“Microsoft Edge will allow Adobe Flash Player to load as a plug-in via the Internet Explorer mode feature.”

NOTE: This is until in the USA Summer, it will be finally axed. So once MS EdgeV88 comes out, I will need to test

Long Term Solution

Using Google Chrome is a dead end

MS Edge using Internet Explorer mode feature should get you through till June see http://britv8.com/enabling-flash-player-after-12th-january-2021/

After June , then the packaged browser via https://services.harman.com/partners/adobe is the adobe recommended option

New Browser Installs

Also note that so far I have found new install of Edge I have done does not download the flash extension, you get a “we could not download” this I assume is because it is being downloaded from Adobe’s site and they have removed all download locations.

Hope this helps someone out there

7 thoughts on “Enabling Flash Player after 12th January 2021

  1. This is really awesome. Thank you for writing it! The IE11 instructions worked for me perfectly the first time. We are in the same boat, legacy enterprise applications that aren’t going away just because the big internet players said so. Cheers.

  2. For chrome, the path is C:\Users\\AppData\Local\Google\Chrome\User Data\Default\Pepper Data\Shockwave Flash\System

    ^ Drop the mms.cfg file there. Note: You may have to create the System folder (I did).

    • Ta, unfortunately this is not working for me, glad it worked for you. Bear in mind V88 of Chrome will break flash for good

  3. You’re a life saver. Appreciate this post – worked like a charm for us. In our case, IE didn’t even need to be closed – just the window w/ the error, then relaunch the Flash-based link.

  4. This is awesome! Thanks for the blog as you are one of the only people that have contributed to this issue of fixing Flash. Just because the source vendor (Adobe,MS, Google,etc) doesn’t support flash in their browser, doesn’t mean that companies still don’t use it. Kronos Timekeeping is a big flash based monstrosity that not everyone can upgrade easily to.

  5. The downside here is that I have to install Edge for exactly one purpose, to access a site that uses Flash.

    This is kind of doubtful as far as utility.

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